Dr. Chan has been awarded a $50,000 grant, which will fund salaries and supplies for two years of an undergraduate research program in solid state chemistry and will lead to publications with undergraduate authors. The future of this work is to apply synthetic strategies to composition space that could have potential thermoelectric materials, which directly supports the overall missions of the Petroleum Research Fund.
Materials design is the ultimate goal of the solid state chemist. A ternary compound with a desired chalcophosphate building block will be reacted with a metal chloride to form a quaternary compound that still retains the initial moiety. Solvothermal synthetic methods will be used to solve the diffusion issues of traditional solid state synthesis and to allow the covalently bound building blocks to remain intact during the reaction. This work will initially target known compounds, KLaP_2 Se_6 , K_3 La(PSe_4 )_2 , and K_2 La(P_2 Se_6 )_0.5 (PSe_4 ), in an attempt to compare solvothermal synthetic methods with well known molten flux methods. A novel building block that contains a polymer-like chalcophosphate, K_2 P_2 Se_6 , has been found to have strong second harmonic generation. Using the building block approach we will attempt to synthesize a quaternary compound that retains the linear chain building block that could be similar to a high pressure polymorph of KTbP_2 Se_6 . The materials will be characterized by X-ray diffraction, Raman spectroscopy, and diffuse reflectance. The speciation of the building blocks in various solvents will be studied by MALDI mass spectrometry and electrospray mass spectrometry.