Crystal growth, low-temperature specific heat, and electronic structure of the filled skutterudite compound ThOs₄As₁₂

ABSTRACT

Single crystals of the filled skutterudite compound ThOs${}_4$As${}_{12}$ were grown by a Cd:As flux method. Low-temperature specific-heat measurement reveals a very small Sommerfeld coefficient of the electronic term $\gamma =3.4\left(3\right)$ mJ/molK${}^2$, indicative of a semiconducting or semimetallic character of ThOs${}_4$As${}_{12}$. A low electronic density of states at the Fermi level is consistent with anticipations based on the Zintl concept for the filled skutterudites as well as with our results of band structure calculations. Investigations of a nonmagnetic material ThOs${}_4$As${}_{12}$ can be relevant to unmask puzzling strong electron correlations in the putative topological Kondo insulator CeOs${}_4$As${}_{12}$.

KEYWORDS:

• ThOs${}_4$As${}_{12}$
• filled skutterudite
• crystal growth
• specific heat
• electronic structure

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

J. Juraszek http://orcid.org/0000-0002-9167-5622

K. Rola http://orcid.org/0000-0002-8404-4806

M. Daszkiewicz http://orcid.org/0000-0002-1619-6146

M. Samsel-Czekała http://orcid.org/0000-0002-5854-767X

T. Cichorek http://orcid.org/0000-0002-1995-7086

Z. Henkie http://orcid.org/0000-0003-3279-272X