Large magnetoresistance and first-order phase transition in antiferromagnetic single-crystalline EuAg$_4$Sb$_2$

Sudip Malick; Hanna Świątek; Joanna Bławat; John Singleton; Tomasz Klimczuk

doi:10.1103/PhysRevB.110.165149

paper

Large magnetoresistance and first-order phase transition in antiferromagnetic single-crystalline EuAg $_{4}$ Sb $_{2}$

arXiv:2406.18252 · doi:10.1103/PhysRevB.110.165149

Abstract

We present the results of a thorough investigation of the physical properties of EuAg $_{4}$ Sb $_{2}$ single crystals using magnetization, heat capacity, and electrical resistivity measurements. High-quality single crystals, which crystallize in a trigonal structure with space group $R 3 ˉ m$ , were grown using a conventional flux method. Temperature-dependent magnetization measurements along different crystallographic orientations confirm two antiferromagnetic phase transitions around $T_{N 1}$ = 10.5 K and $T_{N 2}$ = 7.5 K. Isothermal magnetization data exhibit several metamagnetic transitions below these transition temperatures. Antiferromagnetic phase transitions in EuAg $_{4}$ Sb $_{2}$ are further confirmed by two sharp peaks in the temperature-dependent heat capacity data at $T_{N 1}$ and $T_{N 2}$ , which shift to the lower temperature in the presence of an external magnetic field. Our systematic heat capacity measurements utilizing a long-pulse and single-slope analysis technique allow us to detect a first-order phase transition in EuAg $_{4}$ Sb $_{2}$ at 7.5 K. The temperature-dependent electrical resistivity data also manifest two features associated with magnetic order. The magnetoresistance exhibits a broad hump due to the field-induced metamagnetic transition. Remarkably, the magnetoresistance keeps increasing without showing any tendency to saturate as the applied magnetic field increases, and it reaches $\sim$ 20000\% at 1.6 K and 60 T. At high magnetic fields, several magnetic quantum oscillations are observed, indicating a complex Fermi surface. A large negative magnetoresistance of about -55\% is also observed near $T_{N 1}$ . Moreover, the $H$ - $T$ phase diagram constructed using magnetization, heat capacity, and magnetotransport data indicates complex magnetic behavior in EuAg $_{4}$ Sb $_{2}$ .

10 pages, 6 figures

Large magnetoresistance and first-order phase transition in antiferromagnetic single-crystalline EuAg $_{4}$ Sb $_{2}$

Abstract

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Cited by in corpus (3)

Large magnetoresistance and first-order phase transition in antiferromagnetic single-crystalline EuAg4​Sb2​

Abstract

References in corpus (13)

Cited by in corpus (3)

Large magnetoresistance and first-order phase transition in antiferromagnetic single-crystalline EuAg $_{4}$ Sb $_{2}$