Investigation of structural, thermodynamic and energy state characteristics of the ZrNi1-xRhxSn solid solution

• Main Authors: Lyubov Romaka, Yuriy Stadnyk, Vitaliy Romaka, Peter-Franz Rogl, Vladimir Romaka, Andriy Horyn
• Format: Article
• Language: English
• Published: Vasyl Stefanyk Precarpathian National University 2018-07-01
• Series: Фізика і хімія твердого тіла
• Online Access: http://journals.pu.if.ua/index.php/pcss/article/view/2877
• ISSN: 1729-4428; 2309-8589

<p>The peculiarities of crystal and electronic structures, thermodynamic and energy state characteristics of the ZrNi_1-<em>_x</em>Rh<em>_x</em>Sn semiconductive solid solution were investigated. It has been shown that in the ZrNiSn compound simultaneously exist two types of structural defects of the donor nature which generate two donor bands with different ionization energy in the band gap: a) the donor band <em>ɛ</em>_D¹, formed as a result of a partial, up to ~ 1%, occupation of 4<em>a</em> position of Zr atoms by Ni atoms (mechanism of “a priori doping”) and deep donor band <em>ɛ</em>_D², formed as a result of partial occupation of the tetrahedral voids by Ni atoms (Vac). The substitution in 4<em>c</em> position of the Ni atoms by Rh ones in ZrNi_1-<em>_x</em>Rh<em>_x</em>Sn generates structural defects of acceptor nature and creates an impurity acceptor band <em>ɛ</em>_A in the band gap, which, in addition to the existence of <em>ɛ</em>_D¹ та <em>ɛ</em>_D² donor bands, makes semiconductor highly doped and strongly compensated. The obtained results allow to understand the mechanisms of electrical conductivity of thermoelectric materials based on <em>n</em>-ZrNiSn and the ways of conscious optimization of their characteristics for obtaining the maximum efficiency of conversion of thermal energy into electric.<strong></strong></p>