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We report crystal growth, AC and DC magnetic susceptibilities [χ(T, H)], magnetization [M(T, H)], and heat capacity [CP(T, H)] measurement results of GdSbTe single crystal. GdSbTe is isostructural to the confirmed nonmagnetic nodal-line semimetal ZrSiS of noncentrosymmetric tetragonal crystal structure in space group P4/nmm (No. 129), but it shows additional long-range antiferromagnetic spin ordering for the Gd spins of S = 7/2 below TN. Both χ(T, H) and CP(T, H) measurements confirm the existence of a long-range antiferromagnetic (AFM) spin ordering of Gd spins below TN ∼ 12 K, and an additional spin reorientation/recovery (sr) behavior is identified from the change of on-site spin anisotropy between Tsr1 ∼ 7 and Tsr2 ∼ 4 K. The anisotropic magnetic susceptibilities of χ(T, H) below TN clearly demonstrate that the AFM long-range spin ordering of GdSbTe has an easy axis parallel to the ab-plane direction. The field- and orientation-dependent magnetization of M(T, H) at 2 K shows two plateaus to indicate the spin-flop transition for H||ab near ∼2.1 T and a metamagnetic state near ∼5.9 T having ∼1/3 of the fully polarized magnetization by the applied field. The heat capacity measurement results yield Sommerfeld coefficient of γ ∼ 7.6(4) mJ/mol K2 and θD ∼ 195(2) K being less than half of that for the nonmagnetic ZrSiS. A three-dimensional (3D) AFM spin structure is supported by the ab initio calculations for Gd having magnetic moment of 7.1 μB and the calculated AFM band structure indicates that GdSbTe is a semimetal with bare density of states (0.36 states/eV fu) at the Fermi level, which is 10 times smaller than the measured one to suggest strong spin-fluctuation.

By both experimental measurements and theoretical calculations, we investigated the magnetic and electronic properties of Li2Cu(WO4)2 as a tungstate-bridged quasi-one-dimensional (1D) copper spin-(1/2) chain system. Interestingly, magnetic susceptibility χ(T) and specific heat measurements show that the system undergoes a three-dimensional antiferromagnetic (AF)-like ordering at TN ≈ 3.7 K, below a broad χ(T) maximum at ∼8.9 K indicating a low-dimensional short-range AF spin correlation. Bonner-Fisher model fitting of χ(T) leads to an AF intrachain exchange constant of J/kB = 15.8 ± 0.1 K, and mean-field theory estimation gives an interchain coupling constant of J⊥/kB = 1.6 K, which supports the quasi-1D nature of this spin system. Theoretical evaluation of exchange coupling constants within the generalized gradient approximation (GGA) plus on-site Coulomb interaction (U) shows that the dominant AF exchange interaction is of ∼13.9 K along the a-axis with weak interchain coupling, in agreement with the experimental result of a quasi-1D spin-(1/2) chain system. The GGA+U calculations also predict that Li2Cu(WO4)2 is a charge transfer-type AF semiconductor with a direct band gap of 1.5 eV.