Metamagnetism

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

Metamagnetism of itinerant d-electrons in YCo2: Investigation of metamagnetic transitions in Y(Co, Al)2

Abstract: The magnetization of Y(Co/sub 1-x/Al/sub x/) intermetallides is studied for strong pulsed magnetic fields or =0.075 at a field whose strength decreases as x increases. The band model for d-electron metamagnetism is used to interpret the results. The metamagnetic transition field 660 kOe and the magnetic moment 1.4 /sub B// (formula unit) which characterize the magnetization curve for YCo2 are found by extrapolating to x = 0. The results are compared with data for other RCo2 compounds for which the cobalt subsystem has similar properties.

Intermediate valence behavior in CeCo9Si4

Abstract: The novel ternary compound CeCo 9 Si 4 has been studied by means of specific heat, magnetization and transport measurements. Single-crystal X-ray refinements reveal a fully ordered distribution of Ce, Co and Si atoms with the tetragonal space group I4/mcm isostructural with other RCo 9 Si 4 . The smaller lattice constants of CeCo 9 Si 4 in comparison with the trend established by other RCo 9 Si 4 is indicative for intermediate valence of cerium. While RCo 9 Si 4 with R = Pr , … Tb , and Y show ferromagnetism and LaCo 9 Si 4 is nearly ferromagnetic, CeCo 9 Si 4 remains paramagnetic even in external fields as large as 40 T, though its electronic specific heat coefficient ( γ ≃ 190 mJ / mol K 2 ) is of similar magnitude as that of metamagnetic LaCo 9 Si 4 and weakly ferromagnetic YCo 9 Si 4 .

Magnetism in rare earth Co2 compounds under high pressures

Abstract: We have studied electrical resistivity anomalies connected with magnetism in RECo2 (RE=Nd, Tb, Er, Ho) compounds in pressures up to 8 GPa. At ambient pressure the former two compounds exhibit a second order magnetic phase transition (SOMPT) at TC, whereas a first order magnetic phase transition (FOMPT) is observed in the latter two. Although TC decreases with pressure in all four compounds, the TC(P) dependence for NdCo2 and TbCo2 differs considerably from this for HoCo2 and ErCo2. For the latter two, Tc vs P data deviate dramatically from the initial linear dependence above a critical pressure Pc to become almost pressure independent at higher pressures. We propose that this is reflecting the loss of Co metamagnetism that is also indicated by the vanishing resistivity drop at Tc for P>4 GPa and by the change from a FOMPT to a SOMPT. A scenario is discussed assuming that for P>Pc the projected Co 3d density of states at EF decreases. Hence the Co moment collapses because the RE-Co-RE exchange channel beco...

Antiferromagnetic properties in (R = Tb, Dy, Ho)

Abstract: X-ray and neutron diffraction measurements confirm that (R = Tb, Dy and Ho) compounds show the tetragonal type of crystal structure. Magnetization and magnetic susceptibility data indicate antiferromagnetic behaviour below the N?el temperatures at 8.5 K in and 3.35 K in . A metamagnetic transition at kOe and T = 4.2 K has been detected in . The other two compounds give at 4.2 K magnetization curves characteristic for paramagnetic materials up to H = 50 kOe. The magnitudes of magnetic moments at H = 50 kOe are smaller than the free ion values for all three compounds. and exhibit at 1.5 K modulated antiferromagnetic order described by two component wavevectors . The magnetic moments are localized on the lanthanide ions and amount at 1.5 K to 7.68(11) and 7.3(3) in and respectively. Diffuse magnetic peaks observed at 1.5 K in the neutron diffraction pattern of indicate that a long-range antiferromagnetic order starts to set up at this temperature.

Metamagnetic Behavior of Manganese Arsenide

Abstract: Between 35° and 125°C there exists a threshold magnetic field strength at which the compound MnAs exhibits a large and steep increase of its net magnetization. At 35°C the threshold field is 40 koe. There is a large hysteresis associated with the magnetization change. This behavior resembles that exhibited by a material that is metamagnetic in the sense of Neel's description. We believe, however, that in this material the existence of a first-order phase transformation is sufficient to account for the magnetic behavior.