Putative hybridization gap in CaMn2Bi2 under applied pressure

Author(s)

Piva, M. M. ; Thomas, S. M. ; Fisk, Z. ; Zhu, J-X ; Thompson, J. D. ; Pagliuso, P. G. ; Rosa, P. F. S.

• Document type: Journal article
• Source: PHYSICAL REVIEW B; v. 100, n. 4, p. 7-pg., 2019-07-08.

Abstract

We report electrical transport measurements on CaMn2Bi2 single crystals under applied pressure. At ambient pressure and high temperatures, CaMn2Bi2 behaves as a single-band semimetal hosting Neel order at T-N = 150 K. At low temperatures, multiband behavior emerges along with an activated behavior typical of degenerate semiconductors. The activation gap is estimated to be Delta similar to 20 K. Applied pressure not only favors the antiferromagnetic order at a rate of 0.40(2) K/kbar, but it also enhances the activation gap at 20 kbar by about 70%. This gap enhancement is typical of correlated narrow-gap semiconductors such as FeSi and Ce3Bi4Pt3, and it places CaMn2Bi2 as a Mn-based hybridization-gap semiconductor candidate. Ab initio calculations based on density functional theory are shown to be insufficient to describe the ground state of CaMn2Bi2. (AU)

• FAPESP's process: 17/25269-3 - High pressure studies in SrFe2As2, CaMn2Bi2 and CeAuBi2 compounds
• Grantee: Mário Moda Piva
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 17/10581-1 - Emergent phenomena in reduced dimension systems
• Grantee: Pascoal Jose Giglio Pagliuso
• Support Opportunities: Special Projects
• FAPESP's process: 15/15665-3 - Studies of orbital differentiation effects in the magnetic and superconducting properties of FeAs based compounds
• Grantee: Mário Moda Piva
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)