12719-61-8Relevant articles and documents
GeAs: Highly Anisotropic van der Waals Thermoelectric Material
Lee, Kathleen,Kamali, Saeed,Ericsson, Tore,Bellard, Maverick,Kovnir, Kirill
, p. 2776 - 2785 (2016)
GeAs and Sn-doped GeAs were synthesized from elements. Both crystallize in a layered crystal structure in the C2/m space group (No. 12) in the GaTe structure type. The crystal structure consists of As-terminated layers separated by van der Waals gaps. 119Sn M?ssbauer spectroscopy reveals that in the doped compound, Sn atoms are situated in a symmetric and homogeneous environment, most probably in the form of Sn2 dumbbells. The anisotropic crystal structure of GeAs leads to highly anisotropic transport properties. High electrical and thermal conductivities were determined along the crystallographic layers. For the perpendicular direction across the layers, a sharp drop of more than an order of magnitude was observed for the transport properties of the GeAs single crystal. As a result, an order of magnitude difference in the figure of merit, ZT, was achieved. High-temperature thermoelectric characterization of the Sn-doped compound reveals a remarkable ZT with a maximum of 0.35 at 660 K.
Analysis of Phase Equilibria in the Si-Ge-As System
Semenova,Zabakhidze,Goncharov
, p. 1435 - 1437 (2008/10/08)
Samples of the Si-Ge-As system were studied by differential thermal analysis and X-ray powder diffraction in order to determine the phase behavior of the system. It is established that triangulation is possible with the use of the stable joins SiAs-GeAs and SiAs-GeAs2, which are eutectic quasi-binary systems. The solid solubility in silicon monoarsenide is less than 3 mol %. The GeAs-GeAs2-SiAs partial system shows a fourphase eutectic equilibrium at 985 K. The As-GeAs2-SiAs secondary system undergoes a peritectic process L + SiAs ? SiAs2 + GeAs2 at 995 K. The liquidus isotherms of the ternary system were calculated in terms of the regular solutions theory.
