Crossover from Kondo semiconductor to metallic antiferromagnet with 5d-electron doping in CeFe2Al10

DOI: 10.1103/PhysRevB.104.144405

Authors: Rajesh Tripathi (ISIS Facility; Jawaharlal Nehru Centre for Advanced Scientific Research) , D. T. Adroja (ISIS Facility; University of Johannesburg) , M. R. Lees (University of Warwick) , A. Sundaresan (Jawaharlal Nehru Centre for Advanced Scientific Research) , S. Langridge (ISIS Facility) , A. Bhattacharyya (Ramakrishna Mission Vivekananda Educational and Research Institute) , V. K. Anand (Helmholtz-Zentrum Berlin für Materialien und Energie; University of Petroleum and Energy Studies) , D. D. Khalyavin (ISIS Facility) , J. Sannigrahi (ISIS Facility) , G. Cibin (Diamond Light Source) , A. D. Hillier (ISIS Facility) , R. I. Smith (ISIS Facility) , H. C. Walker (ISIS Facility) , Y. Muro (Toyama Prefectural University) , T. Takabatake (Hiroshima University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 104

State: Published (Approved)
Published: October 2021
Diamond Proposal Number(s): 17953

Abstract: We report a systematic study of the 5 d -electron-doped system Ce ( Fe 1 − x Ir x ) 2 Al 10 ( 0 ≤ x ≤ 0.15 ) . With increasing x , the orthorhombic b axis decreases slightly while accompanying changes in a and c leave the unit cell volume almost unchanged. Inelastic neutron scattering, along with thermal and transport measurements, reveal that for the Kondo semiconductor CeFe 2 Al 10 , the low-temperature energy gap, which is proposed to be a consequence of strong c − f hybridization, is suppressed by a small amount of Ir substitution for Fe and that the system adopts a metallic ground state with an increase in the density of states at the Fermi level. The charge or transport gap collapses (at x = 0.04 ) faster than the spin gap with Ir substitution. Magnetic susceptibility, heat capacity, and muon spin relaxation measurements demonstrate that the system undergoes long-range antiferromagnetic order below a Néel temperature T N of 3.1(2) K for x = 0.15 . The ordered moment is estimated to be smaller than 0.07(1) μ B /Ce, although the trivalent state of Ce is confirmed by Ce L 3 -edge x-ray absorption near edge spectroscopy. It is suggested that the c − f hybridization gap, which plays an important role in the unusually high ordering temperatures observed in Ce T 2 Al 10 ( T = Ru and Os), may not be necessary for the onset of magnetic order with a low T N seen here in Ce ( Fe 1 − x Ir x ) 2 Al 10 .

Journal Keywords: Kondo effect; Magnetism; Thermal properties; Transport phenomena; Heavy-fermion systems; Inelastic neutron scattering

Diamond Keywords: Antiferromagnetism; Semiconductors

Subject Areas: Materials, Physics


Instruments: B18-Core EXAFS

Other Facilities: MERLIN, GEM, MuSR and WISH at ISIS

Added On: 07/10/2021 13:17

Discipline Tags:

Quantum Materials Physics Hard condensed matter - structures Magnetism Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) X-ray Absorption Near Edge Structure (XANES)