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Electron Poor Materials Research Group EPM RG. Updates of Experiments --- Synthesis of B, SiB 3 , ZnSb… --- Property measurements of (ZnSnSb 2 ) 1-x (InSb) 2x. Complex-Structured Materials and their Electron Densities. Less # of electrons per atom. Group III + Group IV SiB 3 ….
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Electron Poor Materials Research Group EPMRG Updates of Experiments --- Synthesis of B, SiB3, ZnSb… --- Property measurements of (ZnSnSb2)1-x(InSb)2x
Complex-Structured Materials and their Electron Densities Less # of electrons per atom Group III + Group IV SiB3… Group III B… Group IV C, Si, Ge… Group II + Group V Zn-Sb… Group III + Group V BN, GaN, GaAs, InSb… Less Polarity More Complex NaTl, BaSi2, NaSi Group II + Group VI ZnS, ZnTe, CdSe, CdTe… NaCl, CaO, KBr …
Experimental Preparation • Boron (a-, b- boron) • b- SiB3 • ZnSb • ZnSnSb2 + InSb (Solid Solution for TE study) 3e- 4e-
Crystallization of Boron In History… & Now… Horn, F. H., et at, J. Electrochemical Soc., 106, 905 (1959)
Making Boron Crystals • HP series sample • Pressurize the Pt-B mixture (45-55) at 2GPa • melted at 1500C then cooled to 1000C • CSSS series sample • Load the Pt-B mixture in the a BN capsule w/t screw-on cap (right) • melted at 1500C then cooled to 1000C for compositions of 45:55 and 50:50
*Slack, G. A.; Hejna, C. I.; Garbauskas, M. F.; et al. Journal of Solid State Chemistry1988, 76, 52-63.
b- SiB3, 3.25e/atom Salvador, J. R.; Bilc, D.; Mahanti, S. D.; et al. Angewandte Chemie International Edition2003, 42, 1929-1932.
b- SiB3 with high pressure Starting mixure: 72 mg of B-Si-Ge at 2:1:1 Pressure: 8GPa Heating Program: Held at 1000C for 1h, cooled to 950C at 5C/h, held at 950C for 2h then quench.
Thermoelectric Chalcopyrite (ZnSnSb2)1-x(InSb)2x + 4Sn x = 0.9, x = 0.85, x=0.8 and InSb
Thermoelectric Chalcopyrite Resistivity of InSb
Thermoelectric Chalcopyrite Resistivity of (ZnSnSb2)1-x(InSb)2x