Magnetic Anisotropy and Spin Rotations inHoxTb1−xFe

Dependence of the magnetization and remanence of single-domain particles on the second cubic anisotropy constant

“…9 is the well expressed singularity in the M r vs T dependence for TϷ85 K. This is exactly the temperature for which the spinreorientation transition of the easiest directions of magnetization from ͗110͘ to ͗111͘ occurs for this compound when increasing T according to the one-ion model theory predictions. 19 The general trend to decrease of M r with the temperature raise is due to the superparamagnetic/ ferromagnetic phase ratio increase with T, which is supported by the rather fast but gradual decrease of the magnetization for Hϭ50 kOe as seen in Fig. 9͑b͒.…”

“…The predicted remanence behavior is compared with the one of a Tb 0.6 Ho 0.4 Fe 2 sample, a rare-earth iron Laves compound representing spin-reorientation transition of the easiest direction of magnetization [19][20][21] from ͗110͘ to ͗111͘ in the vicinity of 85 K.…”

“…Both K 1 and K 2 are temperature dependent, K 1 can pass through zero at a certain temperature, so the ͉K 2 /K 1 ͉ ratio can be very high in some temperature range; in such cases one must take into account the term containing K 2 in the energy expression in order to explain the magnetic behavior of the material. Rare-earth iron garnets 18 and rare-earth iron ternary cubic Laves phase compounds [19][20][21] are examples of such magnetic systems. Some numerical results on the influence of K 2 on the hysteresis loops of noninteracting single domain particles have been reported by Usov and Peschany 7 and by García-Otero et al 22 In this article, we present detailed model calculations of the magnetization and remanence curves for a disordered system of noninteracting single-domain particles with cubic anisotropy, taking into consideration both the first and the second anisotropy constants.…”

Magnetic and hydrogen ordering in the frustrated Laves hydridesRMn2H4.5Goncharenko1, Mirebeau2, Irodova3 et al. 1999Phys. Rev. B449390View full textAdd to dashboardCite

“…18 When considering only the fourth term, the energy is minimized for the directions of ͓1 0 0͔, ͓1 1 0͔ or ͓1 1 1͔, depending on the type of rare earth and on the crystal-field parameters. 19 The above directions in the cubic cell correspond to the directions ͓1 Ϫ1 1͔, ͓1 0 0͔, and ͓1 1 1͔ of the rhombohedral unit cell, i.e., the directions observed in Ho, Tb, and Dy samples, respectively, at TϽT R ͑Fig. 9͒.…”

“…[19][20][21] In both RMn 2 D 4.3 and RFe 2 systems, stable moments exist on the transition metals T, the R-T interactions are much smaller than the T-T ones, and the R-R interactions are negligible. However, in the RFe 2 compounds ferrimagnetic structures are observed, the spin directions are imposed by the R anisotropy up to the Néel temperature, and the Fe anisotropy only induces small shifts in the boundaries of the spin orientation diagrams.…”