PHASE EQUILIBRIUM IN YbTe–Yb3Ge5 SYSTEM

• Published in: IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA Vol. 60; no. 1; p. 64
• Main Author: Mukhtarova, Ziyafat M.
• Format: Journal Article
• Language: English; Russian
• Published: 30.01.2017
• ISSN: 0579-2991; 2500-3070
• DOI: 10.6060/tcct.2017601.5144

For citation:Mukhtarova Z.M. Phase equilibrium in Ybte–Yb3Ge5 system. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 64-67.Study of properties of semiconductors developed in close connection with their technical applications.  The present work was devoted to study of phase equilibria and character of interaction in YbTe–Yb3Ge5 system. The section of YbTe–Yb3Ge5 in ternary system Ge–Te–Yb is not only scientific, but also practical interest. The section of YbTe–Yb3Ge5 was studied by methods of physical-chemical analysis: differential-thermal (DTA), high temperature differential-thermal (HTDT), X-ray phase, microstructural analysis (MSA), as well as measurement of density and micro hardness. DTA was performed with pyrometer HTP-75 in quartz ampoule pimped off till 0.1333 Pa. HTDT was performed with HTDT-8m (Tmelt.≥1500÷2000K) by analogical method. X-ray phase analysis was performed by powder method with X-ray diffractometer DRON-2 (CuKα- radiation with Ni-filter). MSA was performed with microscope MIM 8. Micro hardness of alloys was measured with micro hardness tester PMT-3.Density of alloys was determined by pycnometer test. During investigations of the system we used germanium B–4, tellurium B–3, ytterbium Yb–1. Alloys were synthesized at 1450–1700 K temperature range and at this temperature ampoule was kept 5–6 h. Cooling was performed slowly. DTA shows that on thermograms of alloys of the system have two effects. Obtained effects are endothermic reversible.For confirming the data of DTA, microstructural analysis, as well as measurement of micro hardness were performed with X-ray analysis. As the data show, at the concentration of 15–80 mol% of Yb3Ge5 monotectic conversion occurs which is confirmed with isothermal line at 1025 K. Thus, it was established that the section of 4YbTe–Yb3Ge5 is quasibinary cross-section of ternary system Ge–Te–Yb and its diagram is related to eutectic type with monotectics.Eutectic of the system 4YbTe–Yb3Ge5 corresponds to composition of 85% mol% of Yb3Ge5 and temperature of 915 K.