Synthesis and structural, magnetic, electric, and thermoelectric characterization of layered Rh1−xIrxTe2 (0≤x≤1)

Abstract

Crystallographic analysis and thermoelectric studies of solid solutions ${\mathrm{Rh}}_{1\text{\ensuremath{-}}x}{\mathrm{Ir}}_{x}{\mathrm{Te}}_{2}$ $(0\ensuremath{\le}x\ensuremath{\le}1)$ are reported. All compositions show layered structures belonging to the $P\overline{3}m1$ space group at room temperature. ${\mathrm{IrTe}}_{2}$ presents a first-order phase transition from the hexagonal to the triclinic lattice ($P\overline{1}$ space group), which is monitored by synchrotron radiation x-ray powder diffraction. In the cooling-down process the transition appears at 240 K while in the warming-up process it begins at 280 K, showing a remarkable hysteresis. All compositions show a strong metallic behavior with enhanced Pauli paramagnetism and two regimes in the electrical resistivity. These regimes are associated with electron-electron scattering (at low temperature $\ensuremath{\rho}\ensuremath{\sim}{T}^{2}$) and electron-phonon coupling (higher temperatures $\ensuremath{\rho}\ensuremath{\sim}T$). The Seebeck coefficient shows hole-type carriers for all the compounds.