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The synthesis and the x-ray diffraction patter, magnetic susceptibility, and electrical resistivity of the orthorhombic phase of SrIr[O.sub.3] is described. The magnetic and electrical properties showed that the orthorhombic SrIr[O.sub.3] perovskite is paramagnetic below 170 K and is metallic above 44 K before a band type metal insulator transition appeared.

The impact of Ir-Mn composition on magnetization, exchange bias and thermal stability of the bottom-pinned spin valves with nano-oxide layers (NOLs) is studied. The system with an approximate Mn content of around 72 percent is shown to exhibit the most favorable exchange bias and thermal stability for the spin valves.

The exchange anisotropy and rotational anisotropy of IrMn/Fe/IrMn exchange-biased structures are determined by using conventional ferromagnetic resonance (FMR) and network analyzer FMR (NA-FMR). The isotropic downward shift of the resonance field has translated to an upward shift of the resonance frequency and is used for boosting the operational frequency of microwave devices by several gigahertz.

Single mode coherent magnetization oscillations are seen in exchange biased IrMn/Co thin films by the pump-probe time-resolved magneto-optical Kerr effect by using moderate intensity pump pulses. The studies have shown that ultrafast laser pulses have induced pinning along the direction of the applied magnetic field.

Irradiation with less than 1.0 keV H ions have improved the properties of IrMn-based spin valves. The studies have shown that in the case of irradiation, the low energy of the lightest H ion has resulted in little intermixing and the interfaces are largely left intact, which has kept the giant magnetoresistance (GMR) values high.

The effect of IrMn exchange bias layer and the magnetization reversal behavior in half-ring NiFe structures are analyzed. It is shown that the hysteresis loops are shifted to one side because of the exchange coupling and the two-step switching seen in the single half-ring film is retained when the relative strength between the exchange field and the shape anisotropy is weak.

An unusual peak in ferromagnetic (FM) thickness dependence of exchange bias properties found for [[Pt/Co].sub.4]-IrMn multilayers (MLs) prepared by magnetron sputtering. The 1/cos [theta] dependence is accounted by considering the strong out-of-plane magnetic anisotropy introduced during the field cooling.

The blocking temperature [T.sub.B] of the high field rotational losses of NiFe/IrMn film systems of low thickness is used for determining the anisotropy constant K of antiferromagnetic (111) textured IrMn films. The behavior of [T.sub.B](t) and the different methods of the blocking temperature of energy losses for determining K are discussed.

The x-ray magnetic circular dichroism (XMCD) spectroscopy with transmission mode of Mn-Ir/ferromagnetic (FM) bilayers is used to investigate the microscopic origin of the uncompensated antiferromagnetic (AFM) spins. The results have shown that the uncompensated Mn components are induced through the exchange interaction between the FM and AFM layers and are localized at the very interface.

The effect of roughness and different degrees of texture on the interlayer and exchange bias coupling fields and on the resistance-area product (R by A) and temperature and bias dependence of conductance and high tunneling magnetoresistance (TMR) and spin valve magnetic tunnel junctions (SV-MTJs) is examined. The results have implied that composition of buffer layers and their sequence can be used as one of the ways to improve the magnetic and tunneling properties of IrMn SV-MTJs.

A type of soft magnetic underlayer (SUL) with negative uniaxial perpendicular magnetic anisotropy that can be fabricated by a simple process and which suppresses both spike noise and wide adjacent track erasure (WATE) is presented. Results of the tests conducted by varying the composition of the SUL to suppress WATE reveal that the perpendicular recording medium fabricated using the CoIr Sul displays substantially lower spike noise and WATE compared to conventional structures.

Density functional theory (DFT) calculations are used to investigate the energetics and the electronic and magnetic properties of iridium nanoparticles in the range of 2-64 atoms. The strong preference for cubic structure among small clusters demonstrates their rigidity indicating that iridium nanoparticles intrinsically do not favor the coalescence process.

The effects of fluorination and the pyridine/pyrazole ratio on the emission and electrochemical properties are studied by preparing mixed (difluro)phenylpyridine/(difluoro)phenylpyrazole tris-cyclo-metalated iridium complexes. The results reveal that increasing fluorination and replacement of pyridine by pyrazole both leads to a widening of the HOMO-LUMO gap and generally leads to a blue shift in emission.

An exchange bias spin valve structure was used with the IrMn exchange bias layer at the top, which enabled in situ magnetoresistance measurements to be carried out as the interferromagentic (AFM) layer was gradually milled away in an argon ion miller. The MR decreased when the thickness was reduced below 3 nm.

Reactions of tungsten-iridium clusters with tungsten phenylethynyl, diruthenium ethynidyl, or ditungsten butadiyndiyl complexes afford a range of products of the same or higher nuclearity. The focus of the study is on molybdenum/tungsten-iridium clusters, reaction with alkynes having afforded products involving alkyne coordination, dimerization, or C triple bond C scission.

The technique for controlling the magnetization direction of a CoFe pinned layer in a spin-valve-type magnetic tunnel junction (MTJ) with an IrMn layer is examined. A postannealing process in the magnetic random access memories manufacturing process is useful for controlling and rearranging the direction of the pinned layer magnetization in magnetic tunnel junctions (MTJs).

The thermally induced changes of the magnetic coupling in an artificial antiferromagnet exchange biased by an antiferromagnetic layer in a magnetic tunnel junction (Mn-Ir/Co-Fe/Ru/Co-Fe/A1Ox/Ni-Fe) is investigated for annealing temperatures up to 450 degree Celsius. The tunneling magnetoresistance increases up to 43.9 percent after annealing at 325 degree Celsius and decreases strongly for higher temperatures.

The formation of an induced 5d magnetic moment on Ir in a new ferromagnetic compound Fe2IrSi is investigated by x-ray magnetic circular dichroism and x-ray absorption spectra measurements at Ir L(sub 2,3) edges at 297 K. The results suggest that Ir possesses a sizable 5d magnetic moment of approximately 0.15 mu(sub B) at 297 K indicating a moment of approximately 0.2 mu(sub B) near 0 K and the exchange interaction between the itinerant 5d electrons of Ir and the 3d electrons of Fe is responsible for the small coercivity of this compound.

The difference in magnetoresistance (MR) property degradation behavior of bottom (B)- and top (T)- synthetic ferrimagnet-based spin-valve (SV) on annealing is examined. The deposition sequence and the grain boundary area were the two major factors for the differences in interfacial energies of IrMn/CoFe and the B-SV featuring less grain boundaries and nonabrupt IrMn/CoFe interface showed better thermal stability.

The effect of oxygen soaking in some layers at different locations on the magnetoresistance (MR) properties of a basic Ta3/NiFe2/IrMn8/CoFe(sub 2.5)/Ru(sub 0.8)/CoFe2/Cu(sub 2.2)/CoFe2/Cu1/Ta(sub 1.5) synthetic spin valves (SVs) system is evaluated. The MR enhancement ratio was probably due to the improvement of the spin-dependent scattering, increasing the spin-dependent transmission coefficient and reducing the diffusion scattering coefficient, after O2 soaking either within the pinned layers or within the spacer layer.

The magnetic properties and spin-wave damping in ferromagnetic (FM)/antiferromagnetic (AF) bilayers of CoFe/IrMn are examined with magneto-optic Kerr effect magnetometry, ferromagnetic resonance (FMR) and Brillouin light scattering (BLS). Application of FMR and BLS measurements in CoFe/IrMn yields for the local interface, coupling an energy of approximately 18 erg/cm(sub 2), which is on the order of the expected atomic exchange coupling and more than two orders of magnitude larger than the macroscopic unidirectional anisotropy energy are measured by several methods.

The magnetic properties of the array of NiFe/IrMN rings, where an asymmetric hysteresis loop was observed are discussed. The existence of the two remanent states was observed, where one is a single domain state and the other is a flux closure state, because the exchange biased rings do have the potential applications in magnetic random access memories.

Exchange-biased multilayers with IrMn thicknesses from 2 to 80 Angstrom with 50-Angstrom Ti over- and underlayers are discussed. IrMn layers grown with a dominant hcp phase show an enhanced effect in the magnetization.

The transmission electron microscopy was used to study the way magnetization reversal proceeds in the ferromagnetic layer for sets of bilayers in which the ferromagnetic layer was of constant thickness of the antiferromagnetic layer was varied. The result reveals no shift fields for IrMn thickness of 20 Armstrong, although significant coercivities were recorded and reversal involved rather simple domain processes.

The IrMn used to stabilize the free layer in exchange tab type magnetic recording readback heads is presented. The two processes used to eliminate the coupling between the exchange tab material (IrMn) and the free layer (NiFe), which creates a sensitive, nonhysteretic, linear, stable free layer.

The reversal process of CoFe/IrMn bilayers using magnetic force microscopy is presented. The effect of the competition between the distributed interfacial ferromagnet/antiferromagnet coupling and the coupling inside the ferromagnetic layer on the nature of the reversal process of the bilayers is presented.

An original concept of high sensitivity magnetic field sensor using the spin-dependent tunneling effect is studied. It is observed that the smooth loss of sensitivity at higher temperature is correlated to the thermal dependence of the exchange bias property when IrMn is deposited above the insulating Al2O3 barrier.

The thermal stability of exchange biasing interaction in antiferromagnetic/ferromagnetic bilayers of Ir(sub 19)Mn(sub 81) and Ni(sub 80)Fe(sub 20) or Co(sub 90)Fe(sub 10) are investigated. It is concluded that the (111) texture is an important factor governing the size of the exchange-biasing field and the thermal stability.