Role of spin-glass behavior in the formation of exotic magnetic states in GdB6

Abstract

Randomness and frustration are believed to be two crucial criteria for the formation of spin glass state. However, the spin freezing occurs in some well-ordered crystals below the related temperature Tf due to the instability of each spin state, which induces the variation of either magnetic moment value or exchange energy. Here we explore the new mechanism of the in-site originated disorder in antiferromagnets Gd0.73La0.27B6 and GdB6, which is caused by the random mutual shifts of Gd3+ spins from the centrally symmetrical positions in the regular cubic lattice. The universal scaling of ESR linewidth temperature dependencies to the power law ΔH(T) ~ ((T − TD)/TD)α with α = − 1.1 ± 0.05 in the paramagnetic phase of both compounds demonstrates the identity of the origin of magnetic randomness. In Gd0.73La0.27B6 the resulting random spin configurations freeze at Tf ≈ 10.5 K where the maximum of magnetization is observed. Below Tf the splitting of ZFC and FC magnetization curves takes place as well as the magnetic state depends on the antecedent sample history. In the case of GdB6 the coherent displacement of Gd ions compete with these random shifts forming an antiferromagnetic (AFM) phase at TN = 15.5 K, which prevails over the spin freezing at Tf ≈ 13 K, expected from the ESR data. The observation of the hysteresis of the ESR spectrum in the AFM phase suggests that its properties may be determined by the competition of two types of AFM orders, which results in formation of stable magnetic domains with nonequivalent positions of AFM Gd pairs at T < 10 K.

Growth and characterization of the magnetic topological insulator candidate Mn2Sb2Te5

“…In comparison with published results by others, the previously reported magnetic moment is 4.04µ B per Mn from neutron diffraction [58], and similar to µ eff = 5.91µ B from magnetic measurements [53]. The consistency between measured and calculated µ eff is due to the intercalation of (MnTe) 2 magnetic layers in unit cell of Sb 2 Te 3 .…”

“…The exchange coupling elucidates a Neel temperature (T N ) at 20 K, which is close to other reported MTIs [50,51]. The temperature dependent magnetic susceptibility of as grown Mn 2 Sb 2 Te 5 single crystal in ZFC and FC protocols at 1 kOe displays an antiferromagnetic transition at T N ∼ 20 K. Further to elucidate the magnetic ordering, the first derivative of temperature dependent susceptibility is plotted and the T N is found to be 20 K with an additional magnetic anomaly at T f ∼ 11 K. This is the signature of Spin-glass behavior which has short-range magnetic ordering reported in magnetic materials [52][53][54]. The extreme points of first derivative are carried out for the exact transition temperatures for ZFC which is shown in figure 8(b).…”

Field-induced successive phase transitions in the J1−J2 buckled honeycomb antiferromagnet Cs3Fe2Ishii1, Narumi2, Matsushita3 et al. 2021Phys. Rev. B7070View full textAdd to dashboardCite

“…In the low-field χ c , the linear T behavior below T N remains up to 2 T. The continuous temperature dependence of magnetic susceptibility may suggest that the directions of spin can change smoothly by the temperature changes. To our best knowledge, a few experimental observations of linear T magnetic susceptibilities have been reported in the spin-glass systems Fe 0.5 Mn 0.5 TiO 3 [40] and GdB 6 [41], and in the iron superconductors LaFeAsO 1-x F x [42,43]. In both systems, the predominant origin of the linear T behavior is thought to be magnetic frustration, which gives rise to innumerable degeneracy of metastable magnetic states causing the unique temperature dependences and the hysteretic magnetization process of Cs 3 Fe 2 Cl 9 .…”