Lachgar Research Group
Fundamental research in the field of materials chemistry plays a critical role in the discovery and application of new and better performing materials. This is achieved in three steps i) synthesis of novel materials with better properties, ii) study their structural, physical, and chemical characteristics, and 3) investigation of their potential applications. Our research program has strong emphasis on synthesis of new inorganic materials, determination of their crystal structure, and study of their physical and chemical properties. The design of new materials from specific modules is the unifying theme between the main two research projects in our laboratory. For more information on these projects see the following web site: http://www.wfu.edu/~lachgar
Hydrothermal Synthesis of Open-frameworks Metal Phosphates and Arsenates
Some metal phosphates and arsenates exhibit interesting physical and chemical properties that are related to their open-framework structures. The existence of interlayer spaces, interconnected tunnels, and different size cavities give these compounds potential applications as absorbents, catalysts, ion exchangers, solid state electrolytes, and non-linear optical materials. Our research in this field aims at low temperature hydrothermal synthesis of novel metal phosphates and arsenates, and their structural characterization. Three types of compounds, binary indium phosphates (In-PO4), ternary indium phosphates (A-In-PO4, A = cation), and mixed indium-transition metal phosphates are investigated. Examples of compounds recently discovered in our group include the layered compound Ca2In(PO4)(HPO4)2·H2O, and the 3D framework compound Ba3In2(HPO4)6.
Synthesis and characterization of cluster-based low-dimensional materials
The aim of this project is to prepare and characterize low-dimensional or open-framework materials containing octahedral metal clusters. The project involves the systematic study of niobium oxychlorides containing octahedral Nb6L18 (L = Cl, O) clusters to reach a fundamental understanding of the correlation between the cluster configuration and the framework dimensionality. The work's broad benefit is in identifying and understanding the structure determining factors that will ultimately lead to making these materials by design. Our strategy is to use a combination of ligands to make compounds with new structure types, and perhaps interesting magnetic or conductivity properties. This approach has led to the successful synthesis of novel compounds with 3D, 2D, and 1D frameworks. Our studies point to the existence of a wealth of compounds with novel frameworks accessible via solid-state high temperature synthesis.
Two examples of layered cluster-based niobium oxychloride recently made in our laboratory