Layered van der Waals Topological Metals of TaTMTe4 (TM = Ir, Rh, Ru) Family

The Journal of Physical Chemistry Letters. 2021. Vol. 12. No. 28. P. 6730–6735.

Shipunov G., Piening B. R., Wuttke C., Romanova T. A., Sadakov A. V., Sobolevskiy O. A., Guzovsky E. Y., Usoltsev A. S., Pudalov V., Efremov D., Subakti S., Wolf D., Lubk A., Buchner B., Aswartham S.

Layered van der Waals materials of the family TaTMTe4 (TM = Ir, Rh, Ru) are
showing interesting electronic properties. We report the growth and characterization of
TaIrTe4, TaRhTe4, TaIr1−xRhxTe4 (x = 0.06, 0.14, 0.78, 0.92), Ta1+xRu1−xTe4 single crystals.
X-ray powder diffraction confirms that TaRhTe4 is isostructural to TaIrTe4. All these
compounds are metallic with diamagnetic behavior. Below T ≈ 4 K we observed signatures of
the superconductivity in the TaIr1−xRhxTe4 compounds for x = 0.92. All samples show weak
quadratic-in-field magnetoresistance (MR). However, for TaIr1−xRhxTe4 with x ≈ 0.78, the
MR has a linear term dominating in low fields that indicates the presence of Dirac cones in the
vicinity of the Fermi energy. For TaRhTe4 series the MR is almost isotropic. Electronic
structure calculations for TaIrTe4 and TaRhTe4 reveal appearance of the Rh band close to the
Fermi level.

Keywords: tellurides, теллуриды