Hysteresis and coercivity of hematite

Magnetic properties of hematite with large coercivity

The magnetic properties of hematite powders produced by a solid state nucleation-and-growth process are studied as a function of temperature T and applied field H. Independently of the temperature, there exists a soft magnetic contribution that is assigned to the canting of spins at the superficial shell of each particle and is not affected by the Morin transition. At 220 < T < TM a magnetic co...

Surface potential of hematite in aqueous electrolyte solution: hysteresis and equilibration at the interface.

Electrostatic potential at the inner plane of the hematite aqueous interface, i.e., surface potential, was measured by means of a single-crystal hematite electrode. Acidic solutions were titrated with base and then back-titrated with acid. Surface potentials were evaluated from electrode potentials by setting the zero value at the isoelectric point. In the case of fast titrations the equilibrat...

Influence of magnetic domain size on dipolar interactions and hysteresis field asymmetry in layered high/low coercivity perpendicular anisotropy systems

Coercivity conditions and variational inequalities

Various coercivity conditions appear in the literature in order to guarantee solutions for the Variational Inequality Problem. We show that these conditions are equivalent to each other and that they are not only sufficient, but also necessary for the set of solutions to be non-empty and bounded.

Thermal synthesis of Hematite nanoparticles: Structural, magnetic and morphological characterizations

Hematite (α-Fe2O3) nanoparticle was synthesized using organometallic compound - ferrocene carboxaldehyde through solventless solid state thermal decomposition technique. The crystal structure, magnetic and morphological properties of the decomposed material were studied using powder X-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, ...