Dept. of Physics and Advanced Research Institute
University of New Orleans
Feb. 01, 2006, 4:00pm, Manning Hall 201
Refreshments served at 3:30pm, Manning Hall 222
As the conventional magnetic recording technology enabled recording densities unforeseeable
only a couple of years ago, there is a lot of effort put in developing new types of
memory that could combine the nonvolatility, high speed and high density. Nonvolatility,
the ability to function in an environment where the power cannot be guaranteed, along
with capacity to withstand radiation does would destroy conventional memory are relevant
properties for military and space applications.
Magnetic random memory (MRAM) is the exponent of such efforts and is essentially a
hybrid between an electronic RAM chip and a hard disk drive that uses magnetism to
store the information but is a solid-state device. This talk summarizes our recent
experimental and theoretical results obtained on the study of magnetization dynamics
in magnetic nanostructured materials for information storage applications.
Magnetization dynamics is one of the key issues of magnetic materials that are part
of new data storage devices. For two-dimensional (2D) devices used in MRAM, the magnetization
dynamics is determined by the 2D magnetization switching properties as the MRAM cells
require that the magnetic field be applied in two dimensions in the plane of the device.
Moreover, study of two-dimensional magnetic switching enables us to determine the
critical curve which provides information about micromagnetic and structural properties
of magnetic systems.
A new sensitive method for critical curve determination of 2D magnetic systems was
proposed. It was shown that this method, based on reversible susceptibility's singularities
detection, is general and can be applied independent of the expression free energy
describing the magnetic system under study.
1. L. Spinu et al., Vectorial mapping of exchange anisotropy in IrMn/FeCo multilayers using the reversible
susceptibility tensor, Phys. Rev. B, Rapid Comm., vol. 68, pp. 220401(R), 2003.
2. L. Spinu et al., Probing two-dimensional magnetic switching in Co/SiO2 multilayers using reversible
susceptibility experiments, Appl. Phys. Lett., vol. 86, pp. 012506, 2005.