Metamagnetism

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

Thin magnetic films

Abstract: Publisher Summary This chapter describes a phenomenology of magnetism. The mathematical dualism between “vortex ring and double layer” leads to two different approaches for the explanation of the magnetic properties of matter. The units of the physical quantities have been developed consequently from empirically found electromagnetic laws. The chapter describes the physical quantities and their units. Solid-state matter can exhibit a unique feature in special cases of atomic neighborhood order: spontaneous magnetization. Atomic moments (usually spin moments) may be aligned parallel (ferromagnetism) or antiparallel (antiferromagnetism) because of quantum-mechanical exchange coupling. Ferromagnetism is characterized by two or more sublattices with an antiparallel orientation of their magnetic moments that do not cancel each other. Other examples of magnetic behavior are metamagnetism, helimagnetism, or superparamagnetism. Many efforts have been made to find a quantum theory of magnetism, and there are two mutually exclusive models: the localized moment model works satisfactorily for rare earth metals, whereas the itinerant electron model describes the magnetic properties of the three-dimensional transition metals and their alloys.

Emergence of metamagnetic transition, re-entrant cluster glass and spin phonon coupling in Tb2CoMnO6

Abstract: The double perovskite compound Tb2CoMnO6has been investigated using x-ray absorption spectroscopy (XAS), Raman spectroscopy, magnetic measurements andab initioband structure calculations. It is observed that both anti-ferromagnetic (AFM) and ferromagnetic (FM) phase coexist in this material. The presence of anti-site disorder (ASD) has been established from the analysis of neutron diffraction data. Moreover, a prominent metamagnetic transition is observed in theM(H) behavior that has been explained with the drastic reorientation of the pinned domain which are aligned antiparallel by the antiphase boundaries (APBs) at zero field. The ASD further gives rise to spin frustration at low temperature which leads to the re-entrant cluster glass ∼33 K. The coupling between phononic degree of freedom and spin in the system has also been demonstrated. It is observed that the theoretical calculation is consistent with that of the experimentally observed behavior.

The Magnetic and Crystallographic Properties of MnAs0.92P0.08

Abstract: The magnetic and crystallographic properties of polycrystalline MnAs0.92P0.08. were studied over a range of temperatures. A gradual distortion of the NiAs to the MnP structure coincides with an anomaly in the susceptibility curve, similar to that found with MnAs. It is suggested that the distortion of the NiAs structure results primarily from anion‐anion bonding. The susceptibility anomaly is attributed to an increase in the strength of the antiferromagnetic exchange coupling resulting from a decrease in Mn‐Mn separation during distortion. The appearance of metamagnetism at low temperatures is shown to be consistent with this view.

Magnetic phase transitions in R5NiPb3 (R=Ce, Nd, and Gd)

Abstract: We report magnetic and thermodynamic measurements for R5NiPb3 (R=Ce, Nd, Gd). Gd5NiPb3 has a transition at 68K, apparently ferrimagnetic from specific heat and magnetization measurements. For Ce5NiPb3, a phase transition is observed in heat capacity at 48 K, with the field dependence of heat capacity and magnetization also indicating ferrimagnetic behavior. Ce5NiPb3 shows metamagnetism at low temperatures, behavior rather similar to Nd5NiPb3 with its previously reported magnetic ordering below 42 K. Using nonmagnetic La5NiPb3, we isolated the magnetic heat capacity for all three materials. The results include a relatively large linear-T term in the specific heat and integrated magnetic entropies consistently smaller than expected.