The purpose of this work was to determine the thermoelectric properties of the pseudobinary system MgfSi-MgfGe. The compositions investigated were Mg2Si, Mg2Ge0.fSi0.s, MgaGe0.4Si0.6, Mg2Ge0.6Si0.4, Mg2Ge0.8Si0.2, and Mg2Ge. X-ray diffraction lattice parameter measurements and differential thermal analysis measurements established the existence of complete solid solubility between Mg~Si and Mg2Ge. Both the lattice parameter and liquidus temperature show almost linear variation with composition in this system. The melting temperature of MgfSi was found to be 1070" ___ 5"C, while that of MgfGe was found to be 1102" _ 5~Electrical resistivity and Hall effect measurements indicated that at 300*K the electron Hall mobility in the mixed crystals is essentially the same as that of the pure compounds. Maximum values obtained were slightly above 300 cm2/volt sec. The forbidden energy gap appeared to vary monotonically from about 0.78 electronvolt (ev) for MgfSi to about 0.70 ev for MgfGe. Thermal conductivity measurements on the pseudobinary system showed that the lattice thermal conductivity of the solid solutions is substantially lower than that of either of the pure compounds at 300~ At this temperature the lattice thermal conductivity of Mg2Ge0.6Sio.4 was found to be 0.0268 watt/cm *K. The maximum thermoelectric figure of merit which could be obtained with these materials is not as good as that of other materials now in use.

The thermal conductivities of relatively large homogeneous samples of Mg2Si and Mg2Ge have been measured in a dynamic calorimeter from 0~ to 300~ In both samples, phonon scattering predominates, and the relationship, kT ~ constant was observed. For Mg2Si, kT ~ 23.4 watts/cm, and for Mg2Ge, ~T -~ 19.8 watts/cm. Although the electrical properties of Mg2Si and Mg2Ge have been measured by several investigators (1-5), the thermoelectric figure of merit for the materials could not be determined because their 1 Present address: Advanced Development Section, Liquid Rocket Plant, Aerojet-General Corporation, Sacramento, California.thermal conductivities had not been measured. In this paper, the results of thermal conductivity measurements made on Mg2Si and Mg2Ge in a dynamic calorimeter are presented.The method which has been used to measure the thermal conductivity is an extensive modification ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.193.164.203 Downloaded on 2014-06-24 to IP

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The phase diagram for the binary system indium-tellurium has been clarified and corrected, particularly in the region near the composition InsTes. This material is a potentially important semiconductor, either alone or in combination with other materials, such as CusTe. AgsTe, CdTe, etc. Results of this study were obtained by correlating differential thermal analysis (DTA), chemical analyses of zone-refined ingots, microscopic analysis, and X-ray determinations. Two new phases have been identified, and the compositions of three other phases have been determined more precisely. (1) The phase InsTe (33.3 at. %Te) does not exist; the composition should be InsTe7 (43 at. %Te). The peritectic decomposition temperature is 462°C. (2) The phase InTe (50.0 at. oA Te) has the composition InsoTesr (50.8 at. 'A Te). The congruent melting point is 696°C. (3) A new phase InsTed (57.0 at. 'A Te) has been found having a peritectic decomposition temperature of 650°C. (4) The phase InaTes (60.0 at. o/o Te) has the composition InwTe4a (59.7 at. ok Te). The congruent melting point is 667"C, and there is a phase transition at about 550°C. (5) A new phase InsTea (62.5 at. 'A Te) has been found, having a peritectic decomposition temperature of 625"C, and a phase transition at 463°C. (6) The phase InsTeg (71.5 at. % Te) was prepared. (7) Electrical measurements on InsTeg show a large conductivity increase associated with the phase transition at 463°C. (8) Electrical measurements on zone refined InsTes, were non-reproducible.

The phase diagram for the binary system normalCdTe‐In2Te3 has been obtained by correlating information from differential thermal analysis measurements, microscopic studies, and x‐ray powder patterns. In establishing the terminal points for this diagram, the melting point for In2Te3 was found to be 667° ±1°C. For normalCdTe , a melting point of 1092° ± 2°C was indicated. In going across the diagram, four peritectic transformations are apparent. The first false(β,CdIn2Te4false) is at 785°C and 50% In2Te3 in normalCdTe ; the second false(γ,CdIn8Te13false) is at about 702°C and 80% In2Te3 in normalCdTe ; the third false(δ,CdIn30Te46false) is at 695°C and about 94% In2Te3 in normalCdTe ; and the fourth false(ε,In2Te3false) occurs at 678°C and about 98% In2Te3 in normalCdTe . There is a large retrograde solubility of CdIn2Te4 in normalCdTe . The ε‐phase transforms to an ε′‐phase at 550 °C in an apparent order‐disorder transition. Electrical measurements on some peritectic compositions from this diagram are reported elsewhere.