Magnetic properties of the Ising dipole ferromagnet LiTbF4

Ultralow-field magnetocaloric materials for compact magnetic refrigeration

“…Due to the weak magnetism of LiTmF 4 , the applied magnetic field was 1000 Oe. LiTbF 4 experienced a FM transition at approximately 2.85 K, which is consistent with previous reports [24][25][26] . The magnetization for all compounds increased upon cooling, but no long-range magnetic order was found for the other fluorides above 1.8 K. Among these seven fluorides, LiTmF 4 exhibited a different tendency, and the ZFC and FC curves of LiTmF 4 showed that magnetization is a temperature-independent phenomenon below 8 K, which is a sign of Van-Vleck paramagnetism 31 .…”

“…The unit cell of LiREF 4 contains two magnetically equivalent trivalent lanthanide ions at sites with S 4 point symmetry. They exhibit exotic physical properties at low temperatures [23][24][25][26][27][28][29][30][31][32][33][34] , such as quantum criticality. In regard to their basic magnetism, they can be categorized into three groups, namely, LiTmF 4 , which is Van-Vleck paramagnetic 31 ; LiTbF 4 and LiHoF 4 , which are ferromagnetic (FM) with Curie temperature (T C ) values of 2.87 and 1.53 K, respectively [24][25][26]28,29 ; and LiDyF 4 , LiErF 4, and LiYbF 4 , which are antiferromagnetic (AFM) with Néel temperature (T N ) values of 0.62, 0.38 and 0.128 K, respectively 27,[30][31][32] .…”

Analysis of the Uniaxial Magnetic Properties of High-Spin d6 Ions at Trigonal Prism and Linear Two-Coordinate Sites: Uniaxial Magnetic Properties of Ca3Co2O6 and Fe[C(SiMe3)3]2

“…Doublet states Φ ± n of any magnetic ion with integer total spin S should have an integer n value greater than zero and hence g n ( ⊥ ) = 0. In this context, it is of interest to consider an archetypal Ising system LiTbF 4 , which has high-spin Tb 3+ (f 8 ) ions at sites with point group S 4 . The ground state of a high-spin Tb 3+ (f 8 ) ion, arising from the 7 F state ( L = 3, S = 3), is characterized by a quasi-doublet consisting of two singlets with the zero-field splitting of 1 cm -1 .…”

“…In this context, it is of interest to consider an archetypal Ising system LiTbF 4 , which has high-spin Tb 3+ (f 8 ) ions at sites with point group S 4 . The ground state of a high-spin Tb 3+ (f 8 ) ion, arising from the 7 F state ( L = 3, S = 3), is characterized by a quasi-doublet consisting of two singlets with the zero-field splitting of 1 cm -1 . The wave functions of this quasi-doublet state are made up mainly of | J z = ±6〉 states with some admixture of | J z = ±2〉 .…”