Superconductivity in the thorium nickel borocarbide ThNiBC

¹ School of Physics, Interdisciplinary Center for Quantum Information, and State Key Lab of Silicon Materials, Zhejiang University - Hangzhou, 310058, PRC
² School of Science, Westlake University - 18 Shilongshan Road, Hangzhou, 310064, PRC
³ Collaborative Innovation Centre of Advanced Microstructures, Nanjing University - Nanjing, 210093, PRC

^(a) E-mail: baizhuoli@zju.edu.cn
^(b) E-mail: ghcao@zju.edu.cn (corresponding autor)

Received: 14 February 2023
Accepted: 18 April 2023

Abstract

We report on the synthesis, crystal structure, physical properties, and first-principles calculations of a new borocarbide ThNiBC. The new compound was synthesized by an arc-melting method, crystallizing in a tetragonal LuNiBC-type structure with an exceptionally low axial ratio of . The physical property measurements indicate that it is a Pauli-paramagnetic metal with significant electron-electron scattering. Bulk superconductivity at T_c = 0.7 K is demonstrated with zero electrical resistivity, Meissner effect, and specific-heat jump. The first-principles calculations reveal a relatively low density of states at the Fermi level with multiple electron-type Fermi surfaces.