2025/09/14 by Wang, Zhuoqun, Cui, Xueling, Treu, Tim +13 · 1 citation
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2509.11091
We synthesize the high-quality Gd3BWO9 single crystal and investigate its lowtemperature magnetic and thermodynamic properties. Below T\rmN = 1.08 K, the anisotropic behavior of magnetic susceptibilities reveals that the Gd3+ moments exhibit the dominant antiferromagnetic coupling along the c-axis, while displaying a ferromagnetic arrangement in kagome plane. With pronounced magnetic frustration, in adiabatic demagnetization refrigeration experiments starting from initial conditions of 9 T and 2 K, Gd3BWO9 polycrystal reaches a minimum temperature of 0.151 K, significantly lower than its T\rmN. Due to the high density of Gd3+ ions (S=7/2), the maximum magnetic entropy change reaches over 50 J kg-1 K-1 under fields up to 7 T in Gd3BWO9, nearly 1.5 times as large as commercial sub-Kelvin magnetic coolant Gd3Ga5O12(GGG). The H-T phase diagram of Gd3BWO9 under H//c exhibits field-induced critical behavior near the phase boundaries. This observation aligns with the theoretical scenario in which a quantum critical point acts as the endpoint of a line of classical second-order phase transitions. Such behavior suggests the importance of further investigations into the divergence of magnetic Grüneisen parameter in the vicinity of critical field at ultralow temperatures.