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Structural Peculiarities and Thermoelectric Study of Iron Indium Thiospinel
Author(s) -
Wyżga Paweł,
Veremchuk Igor,
Bobnar Matej,
Koželj Primož,
Klenner Steffen,
Pöttgen Rainer,
LeitheJasper Andreas,
Gumeniuk Roman
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201905665
Subject(s) - ternary operation , octahedron , thermoelectric effect , materials science , crystallography , indium , effective nuclear charge , vacancy defect , ionic radius , crystal structure , chemistry , ion , physics , metallurgy , thermodynamics , organic chemistry , computer science , programming language
The homogeneity range of ternary iron indium thiospinel at 873 K was investigated. A detailed study was focused on two distinct series ( y = z ): 1) a previously reported charge‐balanced (In 0.67+0.33 y □ 0.33−0.33 y ) tetr [In 2− z Fe z ] oct S 4 (A1‐series; □ stands for vacancy; the abbreviations “tetr” and “oct” indicate atoms occupying tetrahedral 8 a and octahedral 16 d sites, respectively) and 2) a new charge‐unbalanced (In 0.67+ y □ 0.33− y ) tetr [In 2− z Fe z ] oct S 4 (A2‐series). Fe atoms were confirmed to exclusively occupy an octahedral position in both series. An unusual reduction of the unit cell parameter with increasing Fe content is explained by differences in the ionic radii between Fe and In, as well as by an additional electrostatic attraction originating from charge imbalance (latter only in A2‐series). The studied compound is an n ‐type semiconductor, and its charge carrier concentration increases or decreases for larger Fe content within the A1‐ and A2‐series, respectively. The thermal conductivity κ tot is significantly reduced upon increasing vacancy concentration, whereas the change of power factor is insufficient to drastically improve the thermoelectric figure of merit.