Itinerant G-type antiferromagnet SrCr₂ As₂ studied by magnetization, heat capacity, electrical resistivity, and NMR measurements

Journal Article · Fri Apr 08 00:00:00 EDT 2022 · Physical Review. B

DOI:https://doi.org/10.1103/physrevb.105.134408· OSTI ID:1868477

Ding, Q. -P. ^[1]; Pakhira, Santanu ^[1]; Sangeetha, N. S. ^[1]; Krenkel, E. H. ^[1]; Timmons, E. I. ^[1]; Tanatar, M. A. ^[1]; Prozorov, R. ^[1]; Johnston, D. C. ^[1]; Furukawa, Y. ^[1]

---

1. Ames Lab., and Iowa State Univ., Ames, IA (United States)

Here, the physical properties of itinerant antiferromagnetic (AFM) SrCr₂ As₂ with body-centered tetragonal ThCr₂Si₂ structure were investigated in single crystalline and polycrystalline forms by electrical resistivity ρ, heat capacity C_p, magnetic susceptibility χ versus temperature T, and magnetization M versus applied magnetic field H isotherm measurements as well as ⁷⁵As and ⁵³Cr nuclear magnetic resonance (NMR) measurements in the wide temperature range T = 1.6–900 K. From the χ(T) and ⁷⁵As NMR measurements, the G-type AFM state below T_N = 615(15) K has been determined, consistent with the previous neutron-diffraction measurements. Direct evidence of magnetic ordering of the Cr spins was shown by the observation of the ⁵³Cr NMR spectrum under H = 0. From the χ( T) measurements on single-crystal SrCr₂ As₂ under the two different magnetic field directions H|| ab and H || c in the AFM state, the Cr ordered moments are shown to align along the c axis in the G-type AFM state. The metallic state is directly evidenced by the ρ, C_p, and NMR measurements, and the density of states at the Fermi energy $$\mathscr{D}$$(E_F) in the AFM state is estimated to be 7.53 states/eV f.u. for both spin directions which is almost twice the bare $$\mathscr{D}$$(E_F) estimated from first-principles calculations, suggesting an enhancement of the conduction-carrier mass by a factor of two in the AFM state. The $$\mathscr{D}$$(E_F) is found to be nearly constant below at least 100 K and is independent of H. The ρ(T) is found to show T-linear behavior above T_N and exhibits positive curvature below T_N where significant loss of spin-disorder scattering upon magnetic ordering is observed. The resistivity anisotropy of the compound remains moderate ρ_c/ρ_a ~ 9 through most of the magnetically ordered phase but shows a rapid increase below 50 K.

• Research Organization: Ames Laboratory (AMES), Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 1868477
• Report Number(s): IS-J-10,804
• Journal Information: Physical Review. B, Journal Name: Physical Review. B Journal Issue: 13 Vol. 105; ISSN 2469-9950
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
antiferromagnetism
magnetic phase transitions
magnetization measurements
nuclear magnetic resonance
resistivity measurements
specific heat measurements
strongly correlated systems
x-ray diffraction