Metamagnetism

About: Metamagnetism is a research topic. Over the lifetime, 2023 publications have been published within this topic receiving 38108 citations.

Chapter 171 Itinerant electron metamagnetism of co sublattice in the lanthanide-cobalt intermetallics

Abstract: Publisher Summary This chapter discusses itinerant electron metamagnetism of Co sublattice in the lanthanide-cobalt intermetallics. The first-order transition (FOT) is observed in several lanthanide-cobalt (R-Co) intermetallics under the effect of varying external parameters and internal parameters. This transition occurs between a nonmagnetic or low-induced moment state and a ferromagnetic state. This phenomenon is called itinerant electron metamagnetism (IEM). The various models to describe IEM are discussed. At the beginning, the basic concepts of the band theory of metamagnetism describing the magnetically uniform states are presented. Then, the role of volume effects and spin fluctuation effects on the metamagnetic behavior are also briefly introduced. The magnetic properties of the systems consisting of both itinerant electrons and localized spins are formulated on the basis of the s-d model. The experimental overview of IEM is given. This section consists of three major parts. The role of the magnetic R-atom as well as the influence of the 3d electrons affecting the character of the magnetic phase transitions and the spin fluctuation scattering is discussed. High-field magnetization in the RCo 2 with one unstable magnetic sublattice is also discussed. IEM in the RCo 3 - and RCo 5 -based compounds is presented.

High Field Magnetization of Quasi One Dimensional Ising Antiferromagnet CsCoCl 3

Abstract: Magnetization of quasi one dimensional Ising antiferromagnet CsCoCl 3 is measured at liquid 4 He temperatures in pulsed high magnetic fields. In the case of an applied field H parallel to the Ising c -axis, the magnetization M at liq. 4 He temperatures shows a metamagnetic transition which is characterized by the sharp double peaks of the field derivative of the magnetization d M /d H at 33.0 T and 43.9 T, respectively. The results are qualitatively explained by the Ising-like linear chain model with small antiferromagnetic inter-chain exchange interaction. The role of the inter-chain interaction is discussed within the framework of molecular field approximation. The temperature dependence and the transverse case of the magnetization process are also studied.

Magnetic ordering in perovskites containing manganese and cobalt

Abstract: The magnetization measurement of systems with the nominal formula (R = Eu, Gd, Tb, Y) has been made. It has been found that and are weak ferromagnets of Dzialoshinsky - Moriya type whereas is an antiferromagnet. The substitution of manganese ions by cobalt ones leads to the appearance of different magnetic states: cluster-spin-glass-like , inhomogeneous ferromagnets with well defined Curie temperatures and again a spin glass state . Spontaneous magnetizations and Curie temperatures reach maxima for compounds with x = 0.5. External magnetic field induces a metamagnetic transition in (R = Gd, Tb, Y). The transition becomes irreversible at low temperature in the Tb- and Y-based compounds. The annealing in vacuum of leads to the increase of the Curie temperature and to the appearance of a metamagnetic transition for the compound. The metamagnetic behaviour is interpreted taking into account the ionic ordering of and ions and possible 3d-orbital ordering in the sublattice.

Inverse and normal magnetocaloric effects in LaFe12B6

Abstract: Intrinsic magnetic properties and magnetocaloric effect were studied for LaFe12B6 itinerant-electron system, which presents an antiferromagnetic ground state below 36 K. For certain magnetic fields values, LaFe12B6 exhibits a sequence of two successive magnetic transitions: an antiferromagnetic-ferromagnetic (AFM-FM) transition at low temperature followed by a ferromagnetic-paramagnetic transition, leading to normal and inverse magnetocaloric effects, respectively. At finite temperatures, both antiferromagnetic (AFM) and paramagnetic states can be transformed into a ferromagnetic (FM) state via a field-induced metamagnetic transition accompanied with a huge magnetic hysteresis. Moreover, we reveal that, at low temperatures, the magnetization displays abrupt jumps across the first-order AFM-FM transition, giving rise to an unusual and unique staircase-like behavior. LaFe12B6 exhibits both normal magnetocaloric effect around the Curie temperature and large inverse magnetocaloric effect around the AFM-FM tra...