Magnetization Process in Dilute Magnetic Oxides

Abstract

Thin films of dilute magnetic oxides often exhibit high-temperature ferromagnetism with magnetization curves of the form tanh( 0 ); the curves are practically anhysteretic and temperature-independent below room temperature. The absence of temperature-dependent coercivity indicates that the magnetization process is dominated by magnetic dipole interactions, not by magnetocrystalline anisotropy. In a model of ferromagnetic grain boundaries, 0 0 14 0 , where 0 is the magnetization of the ferromagnetic regions. Quantitative analysis of more than 200 films of different oxides reveals that only a few percent of the volume of these films is magnetically ordered.

Engineering two-dimensional electron gases at the (001) and (101) surfaces ofTiO2anatase using light

“…Whether or not a magnetic order is also present at the oxygen-deficient surface of TiO 2 anatase cannot be deduced from the ARPES data presented in this paper. Note that magnetic order in thin films of TiO 2 due to oxygen vacancies was previously observed and discussed [41][42][43][44][45][46], and is thus a potential reason for the observed splitting of the d xy -bands. Further experimental work is necessary to clarify the possible magnetism at the oxygen-deficient surface of TiO 2 anatase.…”

Emergent ferromagnetism in ZnO/Al2O3 core-shell nanowires: Towards oxide spinterfaces

“…In the interface regions, unpaired electrons from the extended defect complexes may play important roles in establishing the local magnetic order, 12 and the magnetic hysteresis is dominated by magnetic dipole interactions instead of the conventional magnetocrystalline anisotropy. 55 It is not surprising that the electronic structure is severely altered on the nanoscale at the interfaces between the nanocrystalline ZnO, Al 2 O 3 , and ZnAl 2 O 4 grains. Consequently, the unbalanced spindependent density of states at the Fermi surface gives rise to the observed magnetic moments.…”

Synthesis and characterization of nanostructured magnetoresistive Ni doped ZnO films

“…Nanostructured clusters of NiO could appear at the center of the arrangement due to Ni distribution into the ZnO structure. Ni inclusions [3] and Oxygen vacancies have been pointed out as factors that provide the magnetic characteristics to the ZnO films [7].…”

“…The DMS enable the link between the magnetic properties and the advanced semiconductor technology [1]. A subgroup of the DMS are the Diluted Magnetic Oxides (DMO) that also exhibit magnetic properties when are doped with any transition metal (TM) [2][3][4][5][6] and even producing magnetic properties through structural defects caused during the synthesis of the films [7,8]. High Curie temperature (T c ) is also another requirement to improve the application of DMS films, whereby as reported in the literature the DMO are candidates to achieve high T c [9][10][11].…”