Magnetic structure

About: Magnetic structure is a research topic. Over the lifetime, 10787 publications have been published within this topic receiving 207143 citations.

Magnetic Structure Determination of CeT2Al10 (T = Ru and Os): Single Crystal Neutron Diffraction Studies

Abstract: Neutron diffraction studies of Ce T 2 Al 10 ( T = Ru and Os), which shows an anomalous transition at T 0 = 27 K for CeRu 2 Al 10 and at 29 K for CeOs 2 Al 10 , have been carried out using single crystal samples of the compounds. In the ordered state below T 0 , obvious superlattice reflections have been found, indicating the appearance of ordered magnetic moments. The magnetic structures of both compounds could be commonly explained with a propagation vector q = (0, 1, 0), where collinear antiferromagnetic moments with magnitudes of 0.42(1) µ B for CeRu 2 Al 10 and of 0.29(1) µ B for CeOs 2 Al 10 are aligned along the c -axis.

Electronic and magnetic structure of thin Ni films on Co/Cu(001)

Abstract: The electronic and magnetic structure of ferromagnetic Ni films grown epitaxially on ultrathin films of Co has been studied by x-ray-absorption spectroscopy (XAS) using circular polarization. The growth morphology of the films was verified using high-resolution low-energy electron diffraction and indicated an incomplete layer-by-layer growth mode for the Co and Ni films deposited on Cu(001). We report the presence of additional peaks in the x-ray magnetic circular dichroism (XMCD) as predicted by the configuration interaction model. The ground-state magnetic moments were obtained from the XMCD sum rules at the Ni $2p$ edge. For a film thickness below 2 ML the number of holes and the spin polarization (spin moment per hole) show a gradual decrease, while the orbital polarization (orbital moment per hole) and the spin-orbit interaction show a gradual increase in magnitude. The 6-eV satellite structure, which is present in the XAS and XMCD of bulk Ni, disappears for submonolayer coverages while the dichroism due to ``diffuse magnetism'' between the ${L}_{3}$ and ${L}_{2}$ edges is strongly enhanced. These observations are ascribed to changes in the hybridization (electronic mixing) as a function of film thickness, which influences the ground-state ${d}^{8}$ weight and the s-state spin polarization. The strongly increased orbital moment per spin provides a good measure for the degree of localization. It is shown that for Ni thin films a localization of the wave function does not lead to an enhancement in the total magnetic moment, but, on the contrary, its value is twice as small as the bulk value.

Novel core-shell structure polyacrylamide-coated magnetic nanoparticles synthesized via photochemical polymerization

Abstract: A novel synthesis method of polymer-coated magnetic nanoparticles was developed. UV-induced photochemical polymerization of acrylamide in magnetite aqueous suspension was performed to obtain core-shell structure polyacrylamide-coated magnetic nanoparticles. The mechanism of UV-induced photochemical coating was discussed. The morphology, crystalline structure and magnetic properties of polyacrylamide-coated magnetic nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM), respectively. Superparamagnetic behaviors, high saturation magnetization and good response to external magnetic field were confirmed by the measurement of magnetic hysteresis curves.

Magnetic phase diagram of magnetoelectric LiMnPO4

Abstract: The nature of the spin-flop (SF) transition in the magnetoelectric quasi-2D Heisenberg system LiMnPO${}_{4}$ is studied in fields applied along the $a$ axis. A refinement of the magnetic structure using neutron diffraction data in the SF phase reveals that the spins reorient from being parallel to the $a$ axis to be nearly along the $c$ axis at magnetic fields between 4 and 4.7 T, depending on temperature. The low-field antiferromagnetic phase boundary is shown to join the spin-flop line tangentially at the so-called bicritical point, where there is a suppression of the ordering temperature. At the bicritical field, we observe an increased intensity of the Lorentz broadened elastic scattering at magnetic Bragg peaks above ${T}_{N}$ as compared to zero field and 10 T, without an increase in peak width. This suggests an increased density of fluctuations at the bicritical field as compared to zero field.