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Development of new high- temperature thermoelectric materials on the basis of Zintl phase of pnictides rare earth elements and transition metals.

Project Status: 3 Approved without Funding
Duration in months: 36 months


Zintl phases form a large family of compounds whose electronic conform to 8-N or Zintl – Klemm concept. This class of materials has been identified as promising for thermoelectric applications. For the last time the problem of energy transmission to the long distances has been very acute and therefore development of new materials became topical. One of new class materials for utilization as high-temperature thermoelectric materials with Zintl bonding( Zintl phase) that employ the pnictides of rare earth elements and have the Yb14MnSb11 structure type.Yb14MnSb11, Yb14MnBi11, and Eu14MnSb11 compounds are considered to be Zintl phases and have unique properties and have generated new scientific ideas, have been obtained from ytterbium and europium pnictides. These compounds have high melting temperatures and their magnetic properties change from paramagnetism to ferromagnetism. Efficiency of these materials for conversion of thermal energy into electrical depends on the dimensionless figure of merit zT, where zT = S2T/rk, , and S = Seebeck coefficient, r = electrical resistivity, and k = thermal conductivity. All these three parameters are interconnected and it is necessary to modify one of them, for example Seebeck coefficient can be increased by the pressure including chemical in order to obtain the maximum value zT. So when antimony is partially replaced by tellurium, zT coefficient if of great interest to develop the effective methods of synthesis to obtain compact samples and characterize the new Zintl phases.
High-temperature thermoelectric materials are becoming increasingly useful for applications such as power generation of deep space probes, sea buoys and remote telecommunications. Thermoelectric devices are considered environmentally- benign - power sources that could provide part of the solution to today’s energy problem.
The main of the project will be synthesis, growing single crystals substance, investigated new Zintl phase based on pnictides of rare earth elements and transition metals, the study of their chemical and physical properties as well as applications as high-temperature thermoelectric materials for energy generation from waste heat sources.
New materials were found by building new phase diagrams, emphasizing new Zintl phases, investigating their thermal, magnetic, electrical properties to develop new technique, particularly to transfer energy to long distances
Effect of suggested project on the progress in this sphere. As we know, issue of thermal energy transformation into electrical, its transmission to the long distances is one of the most important goals of science and engineering. As a result of synthesis of new materials that promote to solve this issue, makes its contributions to the progress o

In the result of the works new materials with high zT will be obtained to transform thermal energy into electrical and to transmit them to long distances. Building of new triple phase diagrams, doping of Yb14MnSb11, Yb14MnBi11, Eu14MnSb11, Eu14MnBi11 will contribute to the development of technological process of these materials considering minimal negative effect made on humans, animals and environment

Scientists (more than 50 %) who earlier have been engaged in development of rocket materials and technologies within the limits of the State programs of the USSR will assist in the project implementation of the project will give opportunities of their activity reorientation on peace researches and provide them with workplaces.During the project implementation previous contacts with leading Science Centers of the Europe, USA, Canada, Japan that are engaged with researches in the field of rare earth elements will be adjusted and continued. It will promote integration of scientists of Tajikistan into the international scientific community and introduction of modern techniques in industry of Tajikistanf this sphere. This type of transformation of thermal energy into electrical is ecologically clean method. Besides, the obtained material will be of scientific value expanding knowledge of interesting class of non-organic compounds formed by electropositive elements and elements with Zintl bonding.

Technical approach and methodology of project implementation is based on unique combination of experimental devices and professional level of the project participants both in the sphere of physic-chemical analysis and technological sphere. Advanced methods and methodology will be applied for investigation process

Participating Institutions


University of California (UCSD)