Comprehensive study of the low-temperature transport properties of polycrystalline Sn_1+xTe (x = 0 and 0.03)

Dorra Ibrahim (1) , Christophe Candolfi (1) , Sylvie Migot (1) , Jaafar Ghanbaja (1) , Anne Dauscher (1) , Gérard Le Caër (2) , Bernard Malaman (1) , Christopher Semprimoschnig (3) , Bertrand Lenoir (1)

1 IJL - Institut Jean Lamour
2 IPR - Institut de Physique de Rennes
3 ESTEC - European Space Research and Technology Centre

We report a detailed investigation of the low-temperature transport properties (5-300 K) on polycrystalline samples of Sn_1+xTe (x = 0 and 0.03) prepared by melt quenching in water and slow cooling. These two different synthetic routes result in variations in the hole concentration over more than one order of magnitude, allowing for a systematic investigation of the influence of Sn vacancies on the transport properties. The results evidence a strong correlation between the details of the synthetic process and the concentration of Sn vacancies. Transmission electron microscopy and Mossbauer spectroscopy show that the excess Sn, which helps to lower the hole concentration, segregates at grain boundaries. Interestingly, Hall-effect measurements reveal that charge transport is dominated near 300 K by alloy scattering regardless of the hole concentration. In addition to dictating the electronic properties, the concentration of Sn vacancies has also a significant impact on the thermal transport, with the magnitude of the low-temperature Umklapp peak observed in the lattice thermal conductivity near 30 K scaling with the concentration of Sn vacancies that act as efficient point-defect scatterers.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Chimie-Physique [physics.chem-ph]

Dorra Ibrahim, Christophe Candolfi, Sylvie Migot, Jaafar Ghanbaja, Anne Dauscher, et al.. Comprehensive study of the low-temperature transport properties of polycrystalline Sn_1+xTe (x = 0 and 0.03). Physical Review Materials, 2019, 3 (8), ⟨10.1103/PhysRevMaterials.3.085404⟩. ⟨hal-02303233⟩