Jennifer Aitken

Professor
Bayer School of Natural and Environmental Sciences
Chemistry & Biochemistry

302A Mellon Hall
Phone: 412.396.1670
aitkenj@duq.edu
http://www.scienceresearch.duq.edu/chem/chemdept/aitken.html

Education:

B.S., Rider University
Ph.D., Michigan State University
Post Doctoral Fellow, Wayne State University
Research

Solid-State Inorganic Materials Chemistry

Our laboratory focuses on the synthesis, structure and physicochemical characterization of new inorganic solid-state materials. In particular we are focusing on phosphides, antimonides, sulfides and selenides. We are investigating several synthetic strategies to further develop these classes of solid-state materials. The underlying theme in our research is the quest for novel materials with unique technologically useful properties. From an academic perspective we wish to develop the chemistry of these systems. In studying structure-property and composition-property relationships among these new materials, we should be better able to predict and design new materials with desired properties. We have identified several areas, discussed below, in which we take an exploratory approach to new materials followed by a developed understanding of the systems and an ultimate predictability in the chemistry.

New Diamond-Like Semiconductors with Novel Magnetic and Optical Properties

New semiconductors with unique qualities and combinations of properties are constantly needed. Our laboratory is pursuing the synthesis and study of new, diamond-like semiconductors (DLS) possessing novel magnetic and optical properties.

Diamond-like semiconductors (DLS) are normal valence compounds based on the structure of diamond. For example, InP is an ordered variant of the diamond structure in which half the carbon sites are occupied by In and the other half by P in an orderly fashion. Further ordered substitutions on the cation and anion sites lead to ternary and quaternary DLS. Reports of quaternary DLS are scarce and their properties are virtually unexplored. The motivation for further research in DLS is the unique optical and magnetic properties expected.


Derivation of diamond-like semiconductors by cross-subtitution.
Evolution from InP to CdGeP2 to CdIn2GeP4.

All diamond-like semiconductors possess a noncentrosymmetric crystal structure, which is the first criterion for second harmonic generation (frequency doubling of light). In the past decade, the ternary diamond-like, chalcopyrite semiconductors have come into prominence because of their potential for nonlinear optical, photovoltaic and luminescent applications. One emerging area of interest is diluted, magnetic semiconductors (DMS) because of the manner in which the magnetic behavior can modify and complement the semiconductor properties.

Noncentrosymmetric Crystal structure of InP viewed down the [101] direction showing all tetrahedra pointing in the same direction.

Compounds with tetrahedral structures represent only a small group of inorganic compounds but they assume a unique position since they are one of the rare groups of inorganic compounds for which all possible chemical compositions can be calculated and for which a set of possible structures can be postulated. There are several rules, including valence electron rules and Pauling's 1st and 2nd rule, which must be obeyed in order for a compound to possess a diamond-like structure. While maintaining the diamond-like structure, we are altering the compositions of these compounds and expecting to find the enhancement or realization of useful properties.

We are synthesizing new II-III2-IV-V4 and I-III-IV2-V4 pnictides. These materials may exist as discrete compounds, or a whole range of solid solutions may be accessible, which can be expressed as II-IV-V2:III-V. The compositional flexibility of these systems allows for the tuning of optical properties, where the formation of a series of solid solutions leads to new materials with a wide range of band gaps. For example, if the nonlinear optical response of the compound is large and the material can be phase-matched, the compositional flexibility can be exploited to tune the bandgap to the desired region of the electromagnetic spectrum. We are measuring the non-linear optical properties of these materials in collaboration with the research group of Dr. Shiv Halasyamani from the University of Houston. We will also prepare diluted magnetic semiconductors based on these new materials.

Two synthetic methods: (1) traditional solid-state, high temperature reactions and (2) salt or metal flux synthesis are used to pursue these new materials. We are also involved in the crystal growth and characterization of the resulting new materials. Conclusions will be drawn concerning structure/composition-property relationships.

Diluted Magnetic Semiconductors

 As we move further towards the miniaturization of electronic and memory devices we look for multifunctional materials. One such area emerging from this rationale is the field of spintronics, where researchers wish to exploit not only the charge carriers of a material but also the spin of those charge carriers. A material with room-temperature ferromagnetism and an existing technology base for use in applications would be an ideal candidate for spin-based devices.

The goal of our project is to predict and synthesize new diluted magnetic semiconductors with technologically useful properties. Diluted magnetic semiconductors (DMS) are, by definition, semiconductors in which one or more cations of a semiconductor are partially substituted by a magnetic ion. A sizable amount of work has been done in the area of binary semiconductors, namely the II-VI and III-V based systems, for example CdTe:Mn and GaAs:Mn. In the II-VI systems, the diluted magnetic semiconductors are usually antiferromagnetic or spin glass. In the case of the III-V based DMS materials, ferromagnetic behavior is observed; however, the magnetic transition temperatures (Tc) are far below room temperature limiting their practical application in spintronic devices, for example 110 K for GaAs:Mn. Furthermore, only a small concentration of Mn can be incorporated in these materials.

We are synthesizing new, ternary diluted magnetic semiconductors with the chalcopyrite structure, which we believe will possess interesting and technologically useful properties. In the course of our investigations we wish to study the effect of the magnetic-ion concentration and the choice of magnetic dopant on the magnetic, structural, thermal, electronic and optical properties of these new materials. To complement this time-consuming synthetic avenue we are incorporating solid-state electronic structure methods. Theoretical calculations will help us gain fundamental insight to these systems, as well as guide us in selecting which systems will be the most promising. We are synthesizing these new materials via simple high-temperature solid-state reactions. We are characterizing these materials and comparing our findings to the calculated properties. This will help to fine-tune our calculations, which will then be used to look into many more new DMS systems.


Crystal structure of Chalcopyrite

This research stands at the cross-roads between chemistry, physics and engineering and exposes the graduate and undergraduate students in my laboratory to characterization methods such as powder X-ray diffraction, magnetic susceptibility, scanning electron microscopy and solid state electronic structure methods. Dr. Jeffry Madura from the Department of Chemistry and Biochemistry here at Duquesne is working together with us on a computational approach to finding diamond-like semiconductor materials with enhanced physical properties. Dr. Monica Sorescu from the Physics Department at Duquesne University has extensive experience in magnetic measurements and is working closely with us on the magnetic property measurements of these materials. The results of this project will provide some insight towards where we should look in the future for new diluted magnetic semiconductor materials.

Development of a New Class of Solid-State Compounds

Our laboratory is also working on the synthesis and characterization of oxothiophosphate materials. Oxothiophosphates are compounds that contain oxidized phosphorus bound to both oxygen and sulfur. There is a practical paucity of oxothiophosphates in the literature, especially considering the overwhelming number of (oxo)phosphate and thiophosphate relatives. Explorations of oxothiophosphates are warranted because of the interesting structural chemistry and physicochemical properties expected.

Since few oxothiophosphates have been synthesized, we are relying heavily upon the established oxo- and thiophosphate chemistry to aid us in developing our synthetic methodologies. Therefore, we are pursuing four synthetic strategies for the discovery of new oxothiophosphates: (1) high temperature solid-state, (2) molten flux, (3) solution, and (4) solvothermal syntheses. In many cases, each technique is expected to yield unique materials not obtainable via the other methods. Solvothermal synthesis using structure-directing organic amines is expected to yield the first inorganic/organic hybrid materials based on oxothiophosphate ligands


The cyclic oxothiophosphate ligands [P4O8S4]4- (left) and [P3O6S3]3- (right).
O atoms are blue, sulfur atoms are yellow and P atoms are purple.

The new oxothiophosphates will be studied both structurally and physicochemically. The structures of these new compounds will be compared and contrasted and correlations between their structures and the ratio of O:S in their anions will be made. In the case where the ratio of O:S can change while maintaining the same structure we can tune in the properties of the resulting materials, for example band-gap energies. Together the new compounds will be studied as a class and generalizations about structure-property and composition-property relationships will be proposed. In addition, similarities to and differences from the all oxygen and all sulfur chemistry will be examined.

Publications
  1. Sinagra, C. W. III; Saouma, F. O.; Otieno, C. O.; Lapidus, S. H.; Zhang, J.-H.; Craig, A. J.; Brant, J. A.; Rosmus, K. A.; Grima-Gallardo, P.; Jang, J. I.; Aitken, J. A. "Synthesis, Structure, Linear and Nonlinear Optical Properties of Noncentrosymmtric quaternary diamond-like semiconductors, Cu2ZnGeSe4 (CZGSe) and the novel Cu4ZnGe2Se7." J. Alloy Compd., 2021 888, 161499. https://doi.org/10.1016/j.jallcom.2021.161499
  2. Bookwala, M.; Gumireddy, A.; Aitken, J. A.; Wildfong, P. L. D. "Single Crystal Structure of Terfenadine Form I." Journal of Chemical Crystallography, 2021. https://doi.org/10.1007/s10870-021-00892-3
  3. Grima-Gallardo, P.; Muñoz, M.; Durán, S.; Delgado, G. E.; Pérez-Cappé, E.; Aitken, J. A.; Rai, D. P. (CuAlSe2)1-x(TaSe)x Alloy System (0  x  0.5): X-ray Diffraction, Differential Thermal Analysis and Scanning Electron Microscopy Measurements. Rev. LatinAm. Metal. Mat. 2021, 41, 34-49. https://www.rlmm.org/ojs/index.php/rlmm/article/view/1071
  4. Delgado, G. E.; Grima-Gallardo, P.; Aitken, J. A.; Cabrera, H.; Cisterna, J.; Cárdenas, A.; Brito, I. "Crystal Structure and Powder X-ray Diffraction Data of the Super-Paramagnetic Compound CuFeInTe3" Revista Mexicana de Física, 2021, 67, 305-311. https://doi.org/10.31349/RevMexFis.67.305
  5. Stoyko, S. S.; Craig, A. J; Kotchey, J. W.; Aitken, J. A. "Synthesis, Crystal Structure and Electronic Structure of Li2PbSiS4, a Quaternary Thiosilicate with a Compressed Chalcopyrite-like Structure." Acta Cryst. 2021, C77, 1-10. https://doi.org/10.1107/S2053229620015338
  6. Delgado, G. E.; Grima-Gallardo, P.; Aitken, J. A.; Cárdenas, A.; Brito, I. The new P-chalcopyrite compound Cu2FeIn2Se5; synthesis, thermal analysis and crystal structure analysis by X-ray powder diffraction. Revista Mexicana de Fisica, 2021,67, 18-24. https://doi.org/10.31349/RevMexFis.67.18
  7. Grima-Gallardo, P.; Delgado, G. E.; Pérez-Cappé, E.; Aitken, J. A.; Rai, D. P. "Synthesis, X-ray diffraction and Magnetic Measurements of Cu(Ni, Co)InS4 Alloys: Superconductor Behavior of CuCo2InS4." Revista LatinoAmericana de Metalurgia y Materiales, 2020,40, 131-141. http://www.rlmm.org/ojs/index.php/rlmm/article/view/1031
  8. Zhang, J.-H.; Stoyko, S. S.; Craig, A. J.; Grima, P. Kotchey, J. W.; Jang, J. I.; Aitken, J. A. "Phase matching, strong frequency doubling and outstanding laser-induced damage threshold in the biaxial, quaternary diamond-like semiconductor Li4CdSn2S7." Chem. Mater. 2020, 32, 10045-10054. https://dx.doi.org/10.1021/acs.chemmater.0c03268
  9. Karuppannan, B.; Sturgeon, J. L.; Bunker, K. L.; Harris, K. E.; Ravi, G.; Aitken, J. A. "Low Temperature Synthesis of Micro- and Nano-crystalline CuFeS2 Polymorphs." SN Applied Sciences, 2020, 2, 1931. https://dx.doi.org/10.1007/s42452-020-03729-4
  10. Zhang, J.-H.; Clark, D. J.; Brant, J. A.; Rosmus, K. A.; Grima, P.; Lekse, J. W.; Jang, J. I.; Aitken, J. A. "-Li2ZnGeS4: A Wide-Bandgap Diamond-like Semiconductor with Excellent Balance between Laser-Induced Damage Threshold and Second Harmonic Generation Response." Chem. Mater. 2020, 32, 8947-8955. (featured on the cover) https://dx.doi.org/10.1021/acs.chemmater.0c02929
  11. Grima-Gallardo, P.; Muñoz, M.; Durán, S.; Delgado, G. E.; Pérez-Cappé, E.; Aitken, J. A. "X-ray Diffraction, Scanning Electron Microscopy and Differential Thermal Analysis of (CuGaSe2)1-x(TaSe)x Alloys System (0 x 0.5)." Senhri Journal of Multidisciplinary Studies, 2020, 5, 1-18. https://doi.org/10.36110/sjms.2020.05.01.001
  12. Craig, A. J.; Stoyko, S. S.; Bonnoni, A.; Aitken, Jennifer A. "Syntheses and Crystal Structures of the Quaternary Thiogermanates Cu4FeGe2S7 and Cu4CoGe2S7." Acta Cryst. 2020, E76, 1117-1121. https://doi.org/10.1107/S2056989020007872
  13. Moroz, N. A.; Bauer, C.; Williams, L.; Olvera, A.; Casamento, J.; Page, A. A.; Bailey, T. P.; Weiland, A.; Stoyko, S. S.; Kioupakis, E.; Uher, C.; Aitken, J. A.; Poudeu, P. F. P. "Insights on the Synthesis, Crystal and Electronic Structures, and Optical and Thermoelectric Properties of Sr1-xSbxHfSe3 Orthorhombic Perovskite." Inorg. Chem. 2018, 57, 7402-7411. https://doi.org/10.1021/acs.inorgchem.8b01038.
  14. Grima-Gallardo, P.; Nieves, L.; Soto, M.; Quintero, M.; Cabrera, H.; Zumeta-Dubé I.; Rodríquez, A.; Aitken, J. A.; Rai, D. P. "Coexistence of Superparamagnetic and Ferromagnetic Components in (CuGa)1-xFeSe2-x Solid Solutions with x=0.1, 1/3 and 1/2." Rev. LatinAm. Metal. Mater. 2018, 38, 128-135. https://www.rlmm.org/ojs/index.php/rlmm/article/view/871
  15. Grima-Gallardo, P.; Méndez, L.; Delgado, G. E.; Cabrera, H.; Pérez-Cappe, E.; Zumeta-Dubé, I.; Rodríquez, A.; Aitken, J. A.; Rai, D. P. "(CuInSe2)1-x(TaSe)x Solid Solutions (0 < X < 0.5): X-ray diffraction, Scanning Electron Microscopy, Differential Thermal Analysis and Magnetic Susceptibility." Int J Exp Spectroscopic Tech 2018, 3:016. https://doi.org/10.35840/2631-505X/8516
  16. Grima-Gallardo, P.; Izarra, O.; Mendez, L.; Torres, S.; Quintero, M.; Cabrera, H.; Perez-Cappe, E.; Zumeta-Dube, I.; Rodriguez, A.; Aitken, J. A. "Preparation and Characterization of (CuInTe2)1-x(TaTe)x Solid Solutions (0<x<1)." J. Alloys Compd. 2018, 747, 176-188. https://doi.org/10.1016/j.jallcom.2018.02.317
  17. Grima-Gallardo, P.; Quintero, M.; Nieves, L.; Cabrera, H.; Perez-Cappe, E.; Zumeta-Dube, I.; Aitken, J. A.; Brant, J. A. "Phase Diagram of (CuInTe2)1-x(FeTe)x Alloys (0  x  0.6)" Rev. LatinAm. Metal. Mater. 2018, 38, 53-63. http://www.rlmm.org/ojs/index.php/rlmm/article/view/817
  18. Aldridge, J. D.; Womick, J. M.; Rosmus, K. A.; Weiland, A.; Aitken, J. A.; Polvani, D. A.; "Phase Identification and Structure Investigation of Novel Quaternary Rare-Earth Substituted Titanates." J. Solid State Chem. 2017, 256, 19-26. https://doi.org/10.1016/j.jssc.2017.08.030
  19. Chen, E. M.; Stoyko, S. S.; Aitken, J. A. Poudeu P. F. P. "Tuning the Optical, Electronic and Thermal Properties of Cu3NbS4-xSex through Chemical Substitution." Inorg. Chem. Front. 2017, 4, 1493-1500. http://doi.org/10.1039/c7qi00264e
  20. Zhang, J.-H.; Clark, D. J.; Weiland, A.; Stoyko, S. S.; Kim, Y. S.; Jang, J. I.; Aitken, J. A. "Li2CdGeSe4 and Li2CdSnSe4: Biaxial Diamond-like Semiconductors with Strong, Infrared Second-order Nonlinear Optical Responses and Laser Damage Thresholds Influenced by Photoluminescence." Inorg. Chem. Front. 2017, 4, 1472-1484. http://doi.org/10.1039/c7qi00004a
  21. Weiland, A.; Zhang, J.-H.; Clark, D. J.; Brant, J. A.; Sinagra, C. W. III; Kim, Y. S.; Jang, J. I.; Aitken, J. A. "Correction: Infrared Nonlinear Optical Properties of Lithium-Containing Diamond-like Semiconductors Li2ZnGeSe4 and Li2ZnSnSe4." Dalton Trans. 2017, 46, 10102-10104. http://doi.org/10.1039/c7dt90127e
  22. Zhang, Q.; Armatas, G. S.; Aitken, J. A. "Mercouri G. Kanatzidis. Thirty Years of Contributions to Materials and Inorganic Chemistry." Inorg. Chem. Front. 2017, 4, 1098-1089. http://doi.org/10.1039/c7qi90018j
  23. Grima-Gallardo, P.; Soto, M.; Izarra, O.; Nieves, L.; Quintero, M.; Delgado, G. E.; Cabrera, H.; Zumeta-Dubé, I.; Rodríguez, Al.; Glenn, J. R.; Aitken, J. A. "Synthesis, Crystal Structure and Magnetic Behavior of CuCo2InTe4 and CuNi2InTe4." Rev. LatinAm. Metal. Mat. 2017, 37, 83-92. pISSN: 0255-6952/eISSN: 2244-7113; http://www.rlmm.org/ojs/index.php/rlmm/article/view/761
  24. Choudhury, A.; Mohapatra, S.; Asi, H. Y.; Lee, S. H.; Hor, Y. S.; Medvedeva, J. E.; McClane, D. L.; Hilmas, G. E.; McGuire, M. A.; May, A. F.; Wang, H.; Dash, S.; Welton, A.; Boolchand, P.; Devlin, K. P.; Aitken, J.; Herbst-Irmer, R.; Petricek, V. "New Insights into the Structure, Chemistry and Properties of Cu4SnS4." J. Solid State Chem. 2017, 253, 192-201. http://doi.org/10.1016/j.jssc.2017.05.033
  25. Grima-Gallardo, P.; Salas, M.; Contreras, O.; Power, Ch.; Quintero, M.; Cabrera, H.; Zumeta-Dubé, I.; Rodríguez, A.; Aitken, J.; Bärmer-Escamilla, W. "Cu3TaSe4 and Cu3NbSe4: X-ray Diffraction, Differential Thermal Analysis, Optical Absorption and Raman Scattering." J. Alloys Compd. 2016, 658, 749-756. http://doi.org/10.1016/j.jallcom.2015.10.283
  26. Delgado, G. E.; Grima-Gallardo, P.; Nieves, L.; Cabrera, H.; Glenn, J. R.; Aitken, J. A. "Structural Characterization of Two New Quaternary Chalcogenides: CuCo2InTe4 and CuNi2InTe4." Materials Research 2016, 19, 1423-1428. http://doi.org/10.1590/1980-5373-mr-2016-0098
  27. Hulien, M. L.; Lekse, J. W.; Rosmus, K. A.; Devlin, K. P.; Glenn, J. R.; Wisneski, S. D.; Wildfong, P.; Lake, C. H.; MacNeil, J. H.; Aitken, J. A. "An Inquiry-Based Project Focused on the X-ray Powder Diffraction Analysis of Common Household Solids." J. Chem. Ed. 2015, 92, 2152-2156. http://doi.org/10.1021/acs.jchemed.5b00008
  28. Devlin, K. P.; Glaid, A. J.; Brant, J. A.; Zhang, J.-H.; Srnec, M. N.; Clark, D. J.; Kim, Y. S.; Jang, J. I.; Daley, K. R.; Moreau, M. A.; Madura, J. D.; Aitken, J. A. "Polymorphism and Second Harmonic Generation in a Novel Diamond-like Semiconductor: Li2MnSnS4." J. Solid State Chem. 2015, 231, 256-266. http://doi.org/10.1016/j.jssc.2015.08.011
  29. Cabrera, H.; Zumeta-Dubé, I.; Korte, D.; Grima-Gallardo, P.; Alvarado, F.; Aitken, J. A.; Brant, J. A.; Zhang, J.-H.; Calderón, A.; Marín, E.; Aguilar-Frutis, M.; Erazo, J. E.; Perez-Cappe, E.; Franko, M. "Thermoelectric Transport Properties of CuFeInTe3." J. Alloys Compd. 2015, 651, 490-496. http://doi.org/10.1016/j.jallcom.2015.08.128
  30. Brant, J. A.; Devlin, K. P.; Bischoff, C.; Watson, D.; Martin, S. W.; Gross, M. D.; Aitken, J. A. "A New Class of Lithium Ion Conductors with Tunable Structures and Compositions: Quaternary Diamond-like Thiogermanates." Solid State Ionics 2015, 278, 268-274. http://doi.org/10.1016/j.ssi.2015.05.019
  31. Zhang, J.-H.; Clark, D. J.; Brant, J. A.; Sinagra, C. W.; Kim, Y. S.; Jang, J. I.; Aitken, J. A. "Infrared Nonlinear Optical Properties of Lithium-containing Diamond-like Semiconductors Li2ZnGeSe4 and Li2ZnSnSe4." Dalton Trans. 2015, 44, 11212-11222. http://doi.org/10.1039/c5dt01635e
  32. Grima-Gallardo, P.; Peña, R.; Nieves, L.; Marcano, G.; Quintero, M.; Moreno, E.; Zhang, J.-H.; Brant, J. A.; Aitken, J. A. "Preparation, Crystal Structure, Thermal Analysis, Scanning Electron Microscopy and Optical Band-Gaps of Cu2GeTe4 and Cu2SnTe4 Alloys." Rev. LatinAm. Metal. Mat. 2015, 35, 259-268. pISSN: 0255-6952; eISSN: 0244-7113; http://www.rlmm.org/ojs/index.php/rlmm/article/view/619
  33. Sorescu, M.; Xu, T.; Burnett, J. D.; Aitken, J. A. "Role of Mechanochemical Milling in FeVO4 Synthesis." J. Magn. Magn. Mater. 2015, 387, 37-45. http://doi.org/10.1016/j.jmmm.2015.03.074
  34. Brant, J. A.; Clark, D. J.; Kim, Y. S.; Jang, J. I.; Weiland, A.; Aitken, J. A. "Outstanding Laser Damage Threshold in Li2MnGeS4 and Tunable Optical Nonlinearity in Diamond-like Semiconductors." Inorg. Chem. 2015, 54, 2809-2819. http://doi.org/10.1021/ic502981r
  35. Brant, J. A.; Massi, D. M.; Holzwarth, N. A. W.; MacNeil, J. H.; Douvalis, A. P.; Bakas, T.; Martin, S. W.; Gross, M. D.; Aitken, J. A. "Fast Lithium Ion Conduction in Li2SnS3: Synthesis, Physicochemical Characterization and Electronic Structure." Chem. Mater. 2015, 27, 189-196. http://doi.org/10.1021/cm5037524 (This article was included in a cross-journal virtual issue "Recent Advances in Battery Science and Technology". To quote the editorial (Chem. Mater. 2015, 27, 4505-4506), "The selection of articles reflects a combination of what is seen as impactful, opening up new directions, or providing deep and important insights.")
  36. Brant, J. A.; dela Cruz, C.; Yao, J.; Douvalis, A. P.; Bakas, T.; Sorescu, M.; Aitken, J. A. "Field-Induced Spin-Flop in Antiferromagnetic Semiconductors with Commensurate and Incommensurate Magnetic Structures: Li2FeGeS4 (LIGS) and Li2FeSnS4 (LITS)." Inorg. Chem. 2014, 53, 12265-12274. http://doi.org/10.1021/ic5011693
  37. Aitken, J. A.; Brant, J. A.; Clark, D. J.; Kim, Y. S.; Jang, J. I. "Impact of Bandgap on Infrared Optical Nonlinearity in Novel Quaternary Chalcogenides: Cu2CdSnS4, α/β-Cu2ZnSiS4 and Li2CdGeS4." in Nonlinear Optics: Fundamentals, Applications and Technological Advances; Wilkins F. Ed.; Nova Science Publishers Inc.: New York (2014). (Pages 1-61) (ISBN: 978-1-63321-948-9)
  38. Rosmus, K. A.; Brant, J. A.; Wisneski, S. D.; Clark, D. J.; Kim, Y. S.; Jang, J. I.; Brunetta, C. D.; Zhang, J.-H.; Srnec, M. N. Aitken, J. A. "Optical Nonlinearity in Cu2CdSnS4 and α/β-Cu2ZnSiS4, Diamond-like Semiconductors with High Laser-Damage Thresholds." Inorg. Chem. 2014, 53, 7809-7811. http://doi.org/10.1021/ic501310d
  39. Jang, J. I.; Clark, D. J.; Brant, J. A.; Aitken, J. A.; Kim, Y. S. "Highly Efficient Infrared Optical Nonlinearity of a Wide-Bandgap Chalcogenide Li2CdGeS4." Opt. Lett. 2014, 39, 4579-4582. http://doi.org/10.1364/OL.39.004579
  40. Burnett, J. D.; Gourdon, O.; Takas, N. J.; Ranmohotti, S.; Poudeu, P. F. P.; Aitken, J. A. "Structure-Property Relationships along the Fe-substituted CuInS2 Series: Enhancement of Thermoelectric Properties." Mater. Chem. Phys. 2014, 147, 17-27. http://doi.org/10.1016/j.matchemphys.2014.03.034
  41. Grima-Gallardo, P.; Peña, R.; Nieves, L.; Marcano, G.; Quintero, M.; Moreno, E.; Brant, J. A.; Aitken, J. A. "Preparation, Crystal Structure and Thermal Analysis of Cu2GeTe4 and Cu2SnTe4 Alloys." Adv. Mat. Sci. & Technol. 2014, 8, 1-9. ISSN1316-2012.
  42. Brant, J. A.; Clark, D. J.; Kim, Y. S.; Jang, J. I.; Zhang, J.-H.; Aitken, J. A. "Li2CdGeS4, a Diamond-like Semiconductor with Strong Second-order Optical Nonlinearity in the Infrared and Exceptional Laser Damage Threshold." Chem. Mater. 2014, 26, 3045-3048. http://doi.org/10.1021/cm501029s
  43. Stoyko, S. S.; Ramachandran, K. K.; Blanchard, P. E. R.; Rosmus, K. A.; Aitken, J. A.; Mar, A. Three Series of Quaternary Rare-Earth Transition-Metal Pnictides with CaAl2Si2-Type Structure: RECuZnAs2, REAgZnP2, and REAgZnAs2." J. Solid State Chem. 2014, 213, 275-286. http://doi.org/10.1016/j.jssc.2014.03.009
  44. MacNeil, J. H.; Massi, D. M.; Zhang, J.-H.; Rosmus, K. A.; Brunetta, C. D.; Gentile, T. A.; Aitken, J. A. "Synthesis, Structure, Physicochemical Characterization and Electronic Structure of Thio-Lithium Super Ionic Conductors, Li4GeS4 and Li4SnS4." J. Alloys Compd. 2014, 586, 736-744. http://doi.org/10.1016/j.jallcom.2013.10.011
  45. Brant, J. A.; Brunetta, C. D.; Aitken, J. A., 5.09 - Chalcogenides and Nonoxides. In: Comprehensive Inorganic Chemistry II (Second Edition), Reedijk, J.; Poeppelmeier, K., Elsevier: Amsterdam, 2013; Vol. 5; p 213-283.
    ISBN 9780080965291 http://doi.org/10.1016/B978-0-08-097774-4.00510-6
  46. Sorescu, M.; Xu, T.; Wade, C.; Burnett, J. D.; Aitken, J. A. "Synthesis and Properties of V2O3-Fe2O3 Magnetic Ceramic Nanostructures." Ceram. Int. 2013, 39, 8441-8451. http://doi.org/10.1016/j.ceramint.2013.04.026
  47. Brunetta, C. D.; Brant, J. A.; Rosmus, K. A.; Henline, K. M.; Karey, E.; MacNeil, J. H.; Aitken, J. A. "The Impact of Three New Quaternary Sulfides on the Current Predictive Tools for Structure and Composition of Diamond-like Materials." J. Alloys Compd. 2013, 574, 495-503. http://doi.org/10.1016/j.jallcom.2013.05.141
  48. Burnett, J. D.; Xu, T.; Sorescu, M.; Strohmeier, B. R.; Sturgeon, J.; Gourdon, O.; Baroudi, K.; Yao, J.-L.; Aitken, J. A. "Location and Oxidation State of Iron in Fe-substituted CuInS2 Chalcopyrites." J. Solid State Chem. 2013, 197, 279-287. http://doi.org/10.1016/j.jssc.2012.08.043
  49. Rosmus, K. A.; Brunetta, C. D.; Srnec, M. N.; Karuppannan, B.; Aitken, J. A. "Synchrotron X-ray Powder Diffraction and Electronic Structure of - and -Cu2ZnSiS4." Z. Anorg. Allg. Chem. 2012, 638, 2578-2584. http://doi.org/10.1002/zaac.201200259
  50. Yao, J.; Rudyk, B. W.; Brunetta, C. D.; Knorr, K. B.; Figore, H. A.; Mar, A.; Aitken, J. A. "Mn Incorporation in CuInS2 Chalcopyrites: Structure, Magnetism and Optical Properties." Mater. Chem. Phys. 2012, 136, 415-423. http://doi.org/10.1016/j.matchemphys.2012.06.066
  51. Brunetta, C. D.; Minsterman, W. C. III; Lake, C. H.; Aitken, J. A. "Cation Ordering and Physicochemical Characterization of the Quaternary Diamond-Like Semiconductor Ag2CdGeS4." J. Solid State Chem. 2012, 187, 177-185. http://doi.org/10.1016/j.jssc.2011.12.032
  52. Yao, J.; Brunetta, C. D.; Aitken, J. A. "Suppression of Antiferromagnetic Interactions through Cu Vacancies in Mn-Substituted CuInSe2 Chalcopyrites." J. Phys.: Condens. Matter 2012, 24, 086006. http://doi.org/10.1088/0953-8984/24/8/086006 (This paper was selected for inclusion in IOP Select. IOP Select is a special collection of journal articles, chosen by the editors based on one or more of the following criteria: substantial advances or significant breakthroughs, a high degree of novelty or significant impact on future research)
  53. Brunetta, C. D.; Karuppannan, B.; Rosmus, K. A.; Aitken, J. A. "The Crystal and Electronic Band Structure of the Diamond-Like Semiconductor Ag2ZnSiS4." J. Alloy Compd. 2012, 516, 65-72. http://doi.org/10.1016/j.jallcom.2011.11.133
  54. Karey, E.; Rosmus, K. A.; Aitken, J. A.; MacNeil, J. "Bis[2,2'-(2-aminoethylimino) di(ethylammonium)] di--sulfido-bis[disulfidostannate(IV)]" Acta Cryst. 2011, E67, m1516-m1517. http://doi.org/10.1107/S1600536811038657
  55. Yao, J.; Takas, N. J.; Schliefert, M. L.; Paprocki, D. S.; Blanchard, P. E. R.; Mar, A.; Exstrom, C. L.; Darveau, S. A.; Poudeu, P. F. P.; Aitken, J. A. "Thermoelectric Properties of p-type CuInSe2 Chalcopyrites Enhanced by Introduction of Manganese." Phys. Rev B. 2011, 84, 075203. http://doi.org/10.1103/PhysRevB.84.075203
  56. Sorescu, M.; Xu, T.; Burnett, J. D.; Aitken, J. A. "Investigation of LaFeO3 Perovskite Growth Mechanism Through Mechanical Ball Milling of Lanthanum and Iron Oxides." J. Mater. Sci. 2011, 46, 6709-6717. http://doi.org/10.1007/s10853-011-5625-2
  57. Rosmus, K. A.; Aitken, J. A. "Cu2ZnSiS4". Acta Cryst. E. 2011, 67(4), i28. http://doi.org/10.1107/S1600536811008889
  58. Yao, J.; Wang, Z.; van Tol, J.; Dalal, N. S.; Aitken, J. A. "Site Preference of Manganese on the Copper Site in Mn-Substituted CuInSe2 Chalcopyrites Revealed by a Combined Neutron and X-ray Powder Diffraction Study." Chem. Mater. 2010 22, 1647-1655. http://doi.org/10.1021/cm902795e
  59. Yao, J.; Kline, C. N.; Gu, H.; Yan, M.; Aitken, J. A. "Effects of Mn Substitution on the Structure and Properties of Chalcopyrite-Type CuInSe2." J. Solid-State Chem. 2009, 182, 2579-2586. http://doi.org/10.1016/j.jssc.2009.07.014
  60. Lekse, J. W.; Moreau, M. A.; McNerny, K. L.; Yeon, J.; Halasyamani, P. S.; Aitken, J. A. "Second Harmonic Generation and Crystal Structure of the Diamond-like Semiconductors Li2CdGeS4 and Li2CdSnS4." Inorg. Chem. 2009, 48, 7516-7518. http://doi.org/10.1021/ic9010339
  61. Aitken, J. A.; Lekse, J. W.; Quinones, R. "Synthesis, Structure and Physicochemical Characterization of a Noncentrosymmetric, Quaternary Thiostannate: EuCu2SnS4." J. Solid-State Chem. 2009, 182, 141-146. http://doi.org/10.1016/j.jssc.2008.09.022
  62. Lekse, J. W.; Leverett, B. M.; Lake, C. H.; Aitken, J. A. "Synthesis, Physicochemical Characterization and Crystallographic Twinning of Li2ZnSnS4." J. Solid State Chem. 2008, 181, 3217-3222. http://doi.org/10.1016/j.jssc.2008.08.026
  63. Takas, N. J.; Slomka, L. E.; Yang, X.; Giles, N.; Aitken, J. A. "A Simple Aqueous Metathesis Reaction Yields New Lanthanide Monothiophosphates." J. Solid State Chem. 2008, 181, 3044-3050. http://doi.org/10.1016/j.jssc.2008.07.035
  64. Fleming, F. F.; Gudipati, S.; Aitken, J. A. "Alkenenitriles: Conjugate Additions of Alkyl Iodides with a Silica-Supported Zinc-Copper Matrix In Water." J. Org. Chem. 2007, 72, 6961-6969. http://doi.org/10.1021/jo0711539
  65. Mastrovito, C.; Lekse, J. W.; Aitken, J. A. "Rapid Solid-State Synthesis of Binary Group 15 Chalcogenides using Microwave Irradiation." J. Solid State Chem. 2007, 180, 3262-3270. http://doi.org/10.1016/j.jssc.2007.09.001
  66. Takas, N. J.; Aitken, J. A. "An In Situ Time of Flight Neutron Powder Diffraction Study of the Humidity Induced Phase Transition in Sodium Monothiophosphate." J. Solid State Chem. 2007, 180, 2034-2043. http://doi.org/10.1016/j.jssc.2007.05.011
  67. Lekse, J. W.; Stagger, T. S.; Aitken, J. A. "Microwave Metallurgy: Synthesis of Intermetallic Compounds via Microwave Irradiation." Chem. Mater. 2007, 19, 3601-3603. http://doi.org/10.1021/cm0707410
  68. Lekse, J. W.; Pischera, A. M.; Aitken, J. A. "Understanding Solid-State Microwave Synthesis using the Diamond-Like Semiconductor, AgInSe2, as a Case Study." Mater. Res. Bull. 2007, 42, 395-403. http://doi.org/10.1016/j.materresbull.2006.09.025
  69. Aitken, J. A.; Tsoi, G.; Wenger, L.; Brock, S. L. "Phase Segregation of MnP in Chalcopyrite Dilute Magnetic Semiconductors: A Cautionary Tale." Chem. Mater. 2007, 19, 5272-5278. http://doi.org/10.1021/cm071454z
  70. Takas, N. J., Aitken. J. A. "Phase Transitions and Second-Harmonic Generation in Sodium Monothiophosphate." Inorg. Chem. 2006, 45, 2779-2781. http://doi.org/10.1021/ic0520216
  71. Aitken, J. A.; Ganzha-Hazen, V.; Brock, S. L. "Synthesis of Cu3P from the Reaction of Red Phosphorus and a Variety of Copper Sources Under Various Solvothermal Conditions." J. Solid State Chem. 2005, 178, 970-975. http://doi.org/10.1016/j.jssc.2004.10.004
  72. Aitken, J. A.; Kanatzidis, M. G. "Interwoven Pair of Open Frameworks in the Thiophosphate K6Yb3(PS4)5." J. Am. Chem. Soc. 2004, 126, 11780-11781. http://doi.org/10.1021/ja0474648 (This article was featured in the "Editor's Choice, Highlights of the Recent Literature" Science, 2004, 305, 1679-1681.)
  73. Iyer, R. G.; Aitken, J. A.; Kanatzidis, M. G. "Noncentrosymmetric Cubic Thio- and Seleno-Germanates: A0.5M1.75GeQ4 (A = Ag, Cu, Na; M = Pb, Eu; Q = S, Se)." Solid State Sci. 2004, 6, 451-459.http://doi.org/10.1016/j.solidstatesciences.2004.03.001
  74. Jayasekera, B.; Aitken, J. A.; Heeg, M. J.; Brock, S. L. "Towards an Arsenic Analog of Hittorf's Phosphorus: Mixed Pnictogen Chains in Cu2P1.8As1.2I2." Inorg. Chem. 2003, 42, 658-660. http://doi.org/10.1021/ic0258936
  75. Aitken, J. A.; Evain, M.; Iordanidis, L.; Kanatzidis, M. G. "NaCeP2Se6, Cu0.4Ce1.2P2Se6, Ce1.33P2Se6 and the Incommensurately Modulated, AgCeP2Se6: New Selenophosphates Featuring the Ethane-Like [P2Se6]4- Anion." Inorg. Chem. 2002, 41, 180-191. http://doi.org/10.1021/ic010618p
  76. Aitken, J. A.; Larson, P.; Mahanti, S. D.; Kanatzidis, M. G. "Li2PbGeS4 and Li2EuGeS4: Polar Chalcopyrites with a Severe Tetragonal Compression." Chem. Mater. 2001, 13, 4714-4721. http://doi.org/10.1021/cm0105357
  77. Aitken, J. A.; Kanatzidis, M. G. "New Information on the Na-Ti-Se Ternary System." Z. Naturforsch 2001, 56b, 49-56.
  78. Aitken, J. A.; Kanatzidis, M. G. "-Na6Pb3(PS4)4, A Noncentrosymmetric Thiophosphate with the Novel Saucer-Shaped [Pb3(PS4)4]6- Cluster, and Its Metastable, 3-Dimensionally Polymerized Allotrope -Na6Pb3(PS4)4." Inorg. Chem. 2001, 40, 2938-2939. http://doi.org/10.1021/ic015511g
  79. Aitken, J. A.; Canlas, C.; Weliky, D. P.; Kanatzidis, M. G. "[P2S10]4-: a Novel Polythiophosphate Anion Containing a Tetrasulfide Fragment." Inorg. Chem. 2001, 40, 6496-6498. http://doi.org/10.1021/ic010664p
  80. Aitken, J. A.; Chondroudis, K.; Young V. G. Jr.; Kanatzidis, M. G. "LiEuPSe4 and KEuPSe4: Novel Selenophosphates with the Tetrahedral [PSe4]3- Building Block." Inorg. Chem. 2000, 39, 1525-1533. http://doi.org/10.1021/ic991090f
  81. Aitken, J. A.; Marking, G. A.; Evain, M.; Iordanidis, L.; Kanatzidis, M. G. "Flux Synthesis and Isostructural Relationship of Cubic Na1.5Pb0.75PSe4, Na0.5Pb1.75GeS4 and Li0.5Pb1.75GeS4" J. Solid State Chem. 2000, 153, 158-169. http://doi.org/10.1006/jssc.2000.8767
  82. Aitken, J. A.; Brown, S; Chondroudis, K.; Jobic, S.; Brec, R.; Kanatzidis, M. G. " Bi4(P2Se6)3: A New Ternary Selenophosphate Obtained in a P2Se5 Flux." Inorg. Chem. 1999, 38, 4795-4800. http://doi.org/10.1021/ic990180h
  83. Cowen, J. A.; Michlin, P.; Kraus, J.; Mahanti, S. D.; Aitken, J. A.; Kanatzidis, M. G. "EuSe2: A Novel Antiferromagnetic Rare-Earth Polychalcogenide." J. Appl. Phys. 1999, 85, 5381-5383. http://doi.org/10.1063/1.369984
  84. Aitken, J. A.; Cowen, J. A.; Kanatzidis, M. G. "Metamagnetic Transition in EuSe2: A New, Metastable Binary Rare-Earth Polychalcogenide." Chem. Mater. 1998, 10, 3928-3935. http://doi.org/10.1021/cm980364e