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We have reported the structural, thermal, microscopic, magnetization, polarization, and dielectric properties of BiFeO3 ceramics synthesized by a rapid liquid-phase sintering technique. Optimum conditions for the synthesis of single-phase BiFeO3 ceramics were obtained. Temperature-dependent magnetization and hysteresis loops indicate antiferromagnetic behavior in BiFeO3 at room temperature. Although saturated ferroelectric hysteresis loops were observed in single-phase BiFeO3 ceramic synthesized at 880 °C, the reduced polarization is found to be due to the high loss and low dielectric permittivity of the ceramic, which is caused by higher leakage current. [ABSTRACT FROM AUTHOR]

Nanoclusters of rocksalt TiO, anatase TiO2, and rutile TiO2 were produced by cluster deposition and examined with transmission-electron microscopy, x-ray diffraction, and magnetization measurements. The clusters are all magnetic at room temperature, but the magnetization is structure- dependent. The hysteresis loops show coercivities that are of the order of 100 Oe and all films show a preferential in-plane magnetization direction. The size dependence of the magnetization was investigated for rutile clusters with average sizes from about 15 to 40 nm. The analysis of the measurements indicates that the magnetism is predominantly located near the surface of the clusters and characterized by a nominal value of 7.6 μB/nm2. [ABSTRACT FROM AUTHOR]

It is demonstrated that the magnetostatic demagnetizing factor is not the only sample-shape dependent contribution to the hysteresis loop. There are also exchange contributions, which lead to interesting effects, particularly in nanostructures. An example is the recently discovered bulging mode in two-phase nanomagnets. The bulging mode exhibits the angular symmetry of the coherent mode, but it is incoherent due to its radial variation and gives rise to negative demagnetizing factors. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents a study that examined the effect of the insertion of nonmagnetic chromium planes on coercivities of thin cobalt films in cobalt/chromium multilayered films. X-ray diffraction patterns of the films of cobalt; Information on the hysteresis loops of a typical film; Magnetic properties of chromium-copper-alloy films.

Studies the magnetization reversal of cobalt/chromium multilayer films by utilizing initial magnetization curves, minor loops, isothermal and direct current demagnetization remanence curves and temperature dependence of the loops. Measurement of the magnetic interactions among the grains; Film preparation and measurements; Comparison with the Stoner-Wohlfarth model for rotation mechanism.

Presents a study that investigated the wavelength and temperature dependencies of the polar Kerr rotation in several uranium-based compounds. Magnetic properties of uranium compounds; Temperature dependence of the Kerr rotation of uranium compounds using light of wavelength; Details of a diagram showing the rotation hysteresis loops of several uranium compounds.

The performance of hard-magnetic nanostructures is investigated by analyzing the size and geometry dependence of thin-film hysteresis loops. Compared to bulk magnets, weight and volume are much less important, but we find that the energy product remains the main figure of merit down to very small features sizes. However, hysteresis loops are much easier to control on small length scales, as epitomized by Fe-Co-Pt thin films with magnetizations of up to 1.78 T and coercivities of up to 2.52 T. Our numerical and analytical calculations show that the feature size and geometry have a big effect on the hysteresis loop. Layered soft regions, especially if they have a free surface, are more harmful to coercivity and energy product than spherical inclusions. In hard-soft nanocomposites, an additional complication is provided by the physical properties of the hard phases. For a given soft phase, the performance of a hard-soft composite is determined by the parameter (Ms - Mh)/Kh. [ABSTRACT FROM AUTHOR]

We have reported the structural, thermal, microscopic, magnetization, polarization, and dielectric properties of BiFeO3 ceramics synthesized by a rapid liquid-phase sintering technique. Optimum conditions for the synthesis of single-phase BiFeO3 ceramics were obtained. Temperature-dependent magnetization and hysteresis loops indicate antiferromagnetic behavior in BiFeO3 at room temperature. Although saturated ferroelectric hysteresis loops were observed in single-phase BiFeO3 ceramic synthesized at 880 °C, the reduced polarization is found to be due to the high loss and low dielectric permittivity of the ceramic, which is caused by higher leakage current. [ABSTRACT FROM AUTHOR]