Metamagnetism

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

Temperature and field dependence of the spin magnetization density inSmMn2Ge2

Abstract: The site specific spin moments in the layered intermetallic compound $\mathrm{Sm}{\mathrm{Mn}}_{2}{\mathrm{Ge}}_{2}$ have been measured directly as a function of field, between 0.02 and 1 T, using the spin-polarized Compton scattering technique at 13, 40, and 230 K. The field dependence of the orbital moment has been determined by comparison at each temperature with magnetometry data. A small finite Sm spin moment is observed at a low applied field of 0.02 T. These data indicate that in the high-temperature ordered phase the rare-earth sites exhibit a small net moment and exhibit paramagnetic behavior with little coupling to the Mn spin sublattice. Our low-temperature, low-field data indicate a change in magnetic order of the Sm site at $\ensuremath{\approx}35\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ that is metamagnetic in nature. However, we find no evidence for a zero-field transition in the Sm sublattice as previously suggested.

Metamagnetic domains and dynamic fluctuations in FeBr2

Abstract: The mixed phase and the regime of non-critical fluctuations of the magnetic phase diagram of FeBr2 is investigated by SQUID susceptometry and light diffraction techniques. The experiments seem to evidence instability of the tricritical point as conjectured recently. The observation of stripe domains and light diffraction below and above Tm=4.6 K and the virtual continuation of the phase transition line to above Tm are in agreement with the occurrence of a critical endpoint at Tm and of a bicritical endpoint at T>Tm.

Gas-solid reaction of Nd(Fe, M)12 (M = Ti, V, Mo) with H, C and N and intrinsic magnetic properties of the interstitially modified compounds

Abstract: The influence of interstitial H, C and N atoms on structure and intrinsic magnetic properties of Nd(Fe,M)12Zy (M = Ti, V, Mo; Z = H, C, N) was studied. Interstitial hydrogen uptake is reversible, expands the lattice and has a small, but positive effect on the intrinsic magnetic properties. Upon C and N absorption, the ThMn12-type crystal structure is preserved in the case of M = Mo, but a decomposition process and strong growth of the content of -Fe is observed at temperatures above 450 ?C for M = Ti or V. Along with this decomposition process, a deterioration of the magnetic properties (measured at room temperature) occurs. For M = Ti or V, the highest values of the Curie temperature, saturation polarization and anisotropy field were found just before the decomposition process starts. For M = Mo, the Curie temperature and anisotropy field have the highest values for Z = N, with maxima for a nitrogen concentration of 1 per formula unit. At low temperatures, the high field magnetization curves of all carburized compounds investigated show a metamagnetic transition when the field is applied perpendicularly to the aligned c-axes of the epoxy bonded powders.

Itinerant Metamagnetism of CeRu2Si2: Bringing Out the Dead. Comparison with the New Sr3Ru2O7 Case.

Abstract: Focus is given on the macroscopic and microscopic experimental works realized during a decade on the clear case of itinerant metamagnetism in the heavy fermion paramagnetic compound CeRu2Si2. Emphasis is made on the feedback between the band structure, the exchange coupling and the lattice instability. Sweeps in magnetic field, pressure and temperature feel the pseudogap of this strongly correlated electronic system as well as its equivalent CeRu2Ge2 at a fictitious negative pressure. Some mysteries persist as the complete observation of the Fermi surface above the metamagnetic field HM and the detection of the dynamical ferromagnetic fluctuation near HM. The novelty of the bilayer ruthenate Sr3Ru2O7 is discussed by comparison. Despite differences in spin and electronic dimensionality many common trends emerge.