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Nanosecond time-resolved absorption in a magnetic field ranging from 0 to 2.0 were performed on a series of covalently linked donor(PXZ)-Ru[(bipyridine).sub.3]-acceptor(diquat) complexes to study spin-orbit coupling effects. The spin-rotational interaction is found to be responsible for the saturating limit of the magnetic-field effect in high fields for PSZ.

Single crystals of TbRh[In.sub.5] are synthesized by using the flux growth method and its structure, transport and physical properties are compared with other magnetic analogues. TbRh[In.sub.5] has strong antiferromagnetic correlations resulting in an ordering temperature much higher than its heavy fermion analogue CeRh[In.sub.5].

The crystal chemistry and magnetic properties of polycrystalline Ba(Sub 3)MRuIrO(sub 9) (M(super 1+) = Li, Na; M(super 2+) = Mg, Ni, Zn; M(super 3+) = Bi, In) are investigated. It is found that there are antiferromagnetic interactions within the phase sharing octahedra that contain a disordered mixure of Ru and Ir on a single crystallographic site.

The crystal chemistry and magnetic properties of mixed ruthenium-iridium triple-perovskite series Ba(sub 3)MRuIrO(sub 9) (M = Y, lanthanides) is described. It is found that Ba(sub 3)Ln(super 3+)RuIrO(sub 9) compounds have less weiss constants, low effective magnetic moments at low temperatures, consistent with antiferromagnetic correlation.

The switching behavior of the amorphous CoFeB/Ru/CoFeB artificial antiferromagnet (AFi) at submicron sizes is investigated, where additional shape anisotropy and the mangnetostatic edge coupling are also considered. The AFi has an increased coercivity with respect to a single layer of amorphous CoFeB and switching asteroids comparable to single layers are observed in samples with a high new moment.

The pinned/biased moments are observed in the superlattices consisting of a ferromagnetic (FM) SrRuO3 (SRO) and an antiferromagnetic (AFM) SrMnO3 (SMO) bilayer. The result will bring new insights in the understanding of the coupling at the AFM/FM interface that can be useful for creating new exotic phenomena at the interfaces of the multilayer.

The inverse magnetoresistance (MR) in Fe/Ru binary-metal multilayer is reported. The experimental result reveals the complexity of the origin of MR and helps to understand the physical nature of magnetotransport and electrotransport in multilayer structure.

Four mixed-valent ruthenium diphosphonates were synthesized and structurally characterized. Magnetic studies show that significant antiferromagnetic exchange are mediated between the [Ru2(hedp2)](super 3-) (S=3/2) units through halide bridges in compounds, Na4[Ru(hedp)2X].16H2O and K3[Ru(hedp)2.(H2O)2].6H2O.

The feasibility of (super 99)Ru NMR spectroscopy as a tool to characterize solid compounds is demonstrated. The results of the first solid state (super 99)Ru NMR investigations of diamagnetic ruthenium compounds are presented.

The synthesis of CoxRh(sub 1-x) and CoxRu(sub 1-x) alloys of nanometric size dispersed in a polymer matrix through the simultaneous decomposition of the organometallic precursors in solution in mild conditions is described. These structural studies enable to find some analogies between three CoM systems (M= Ru, Rh, Pt).

The ruthenium oxyl radical complex, [Ru(super II)(trpy)(Bu2SQ)O.(super -)] (trpy = 2.2';6'2' -terpyridine, Bu2SQ = 3,5-di-tert-butyl-1, 2-benzosemiquinone) was prepared by double deprotonation of the aqua ligand of [Ru(super III)(trpy)(Bu2SQ)(OH2)](CIO4)(sub 2). The resultant [Ru(super II)(trpy)(Bu2SQ) O.(super -)] showed antiferromagnetic behavior with a Ru(super II)-semiquinone moiety and oxyl radical, the latter of which was characterized by a spin trapping technique.

The effects of the modifications on the coordination mode of the thiosemicarbazone ligands, as observed in a family of complexes of type [M(bpy)(sub 2)(tsc)](super +) (M = Ru, Os), is described. The coordination mode of thiosemicarbazones (Htsc, 1) is observed to be directed by the steric bulk of the alkyl/aryl (R) trans to the hydrazinic nitrogen.

Various experiments are conducted to analyze the influence of the crystallographic shear planes on the magnetic and superconducting behavior in the bulk sample of Ru[Sr.sub.2]Eu[Cu.sub.2][O.sub.8]. The results prove that these shear planes are mainly responsible for producing the anomalies in the samples.

The switching fields and thermal stability of CoPt/Ru dot arrays with various dot thickness [delta] (5-20 nm) were experimentally investigated as a function of the dot diameter, D, (130-300 nm). All dot arrays showed a single domain state, even after removal of an applied field equal to the remanence coercivity [H.sub.r]. The angular dependence of [H.sub.r] for the dot arrays indicated coherent rotation of the magnetization during nucleation. We estimated the values of the 'intrinsic' remanence coercivity Ho obtained by subtracting the effect of thermal agitation on the magnetization and the stabilizing energy barrier to nucleation [E.sub.o]/([k.sub.B] T). The variation in [H.sub.o] as a function of [delta] and D was qualitatively in good agreement with that of the effective anisotropy field at the dot center [H.sup.eff.sub.k] (r = 0), calculated taking account of the demagnetizing field in the dots. The ratio of [H.sub.o] to [H.sup.eff.sub.k] (r = 0) for the dot arrays with [delta] = 10 nm increased from 0.53 to 0.70 as D decreased from 300 to 140 nm, and no significant difference in the [H.sub.o] to [H.sup.eff.sub.k] (r = 0) ratio due to the difference in 6 was observed. On the other hand, [E.sub.o]/([k.sub.B] T) decreased as [delta] decreased. [E.sub.o]/([k.sub.B] T) increased slightly as D decreased, but, was not so sensitive to D over the present D range. Index Terms--CoPt perpendicular films, dot arrays, remanence coercivity, single domain, thermal stability, patterned media.

The occurrence of ferromagnetism is studied in the Ca[Ru.sub.1-x][Fe.sub.x][O.sub.3] system by means of magnetic Compton scattering. The magnetic Compton scattering experiment revealed the occurrence of a large magnetic moment on Ru and an antiferromagnetic coupling between Fe and Ru spin moments.

A Ru-SiO2 intermediate layer is introduced between Ru and recording layers to reduce the intermediate layer thickness of CoCrPt-SiO2 perpendicular recording media. A structural analysis revealed that the Ru-SiO2 intermediate layer enhanced the oxide segregation in the initial growth region of the recording layer.

The first example of a diruthenium phosphonate showing kagome structure is reported. The compound contained kagome layers that are linked by very strong hydrogen bonds into a nanoscale kagome structure and the ferromagentics interactions are mediated between the paramagnetic diruthenium units.

A novel Ru/Ru-oxide interlayer structure was investigated to improve intergranular decoupling in a magnetic layer. The effect of this interlayer on the microstructure, and magnetic properties of CoCrPtO perpendicular media is reported. By using a Ru-oxide layer on a conventional Ru layer, the interlayer grain size was 11 nm. The resulting vertical c-axis dispersion of the interlayer was less than 3[degrees] with no disruption in epitaxial growth throughout the Ru/Ru-oxide and Ru-oxide/magnetic layer interfaces. Grain clusters in the CoCrPtO magnetic layer were observed to match one-to-one with interlayer grains, and were well isolated from each other by nonmagnetic oxide phase grain boundaries. A high coercivity (over 6.9 kOe) and a nucleation field of -2.8 kOe were obtained with this Ru (26 nm)/Ru-oxide (2 nm) interlayer structure. Index Terms--CoCrPtO perpendicular media, exchange decoupling, interlayer, magnetic properties, microstructure, ruthenium, transmission electron microscopy.

(Super 115)In nuclear quadrupole resonance (NQR) measurements were used for examining the heavy fermion Ce(sub 1-x)Y(sub x)RhIn5 and Ce(sub 1-x)La(sub x)RhIn5. T(super -1)(sub 1)'s stay temperature independent below 4.2 K and the observed linewidths of (super 115)In become broader with decreasing temperature for Ce0.5La0.5RhIn5 and Ce0.25La0.75RhIn5.

The low-temperature electrical conductivity in a series of SrRuO3 epitaxial thin films is examined. The films display a well-defined resistivity minimum at low temperature and a conventional metallic behavior is observed at relatively high temperature.

The nature of the magnetic phase and electrical transport in the light of metal insulator transition (MIT) exhibited by similar systems is investigated. It was seen that Ru doping enhances the coercive field, remanant magnetization and Curie temperature T(sub c) while decreasing the high field saturation magnetization.

The enhancement in magnetoresistance ratio in the equiatomic B site composition is due to the onset of double exchange mediated ferromagnetic interaction. Double-exchange interactions induced in SrRuO(sub 3) perovskite by doping Mn ion is the observation made.

Single-crystal MgO substrate is used for examining the origin of high coercivity in a Co-Pt film deposited on Ru underlayer. The use of Ru underlayer in the Pt-rich composition leads to an increase in the anisotropy field which in turn enhances coercivity.

The magnetic properties and associated magnetocaloric properties of GdRu2Ge2 are discussed. Large adiabatic temperature change of 10 K is observed for a field change from 0 to 15 T.

The magnetic and transport properties of RuSr2GdCu2O(sub 8-delta) (Ru-1212) system is discussed. Magnetoresistance is found to be negative above the Ru magnetic ordering temperature of 135 K whereas it displays a positive peak in low fields and turns negative in higher fields below the temperature of 135 K.

The magnetic field generated by a current on chip at the location of the spin dependent tunneling (SDT) element is calculated depending on the geometric parameters of the current line and for the critical current density. No magnetic stability of the Ru/CoFe hard magnetic layer based tunneling system was measured during unidirectional switching.

Magneto-optical indicator film technique was used for examining the magnetization reversal in coupled ferromagnetic Co/Ru/Co trilayers deposited on obliquely sputtered Ta underlayers. An anomalous magnetization reversal was observed and the angle between the magnetization vectors in the adjacent domains was revealed to be plusmn 100 degree.

The resistivity of sputtered Ru, the spin-diffusion length in Ru layers, the interface specific resistances of Cu/Ru and Co/Ru interfaces and the spin-scattering anisotropy at Co/Ru interfaces are examined. Due to the two additional Co/Ru interfaces, the total AR increased by ~1 f omega m(super 2).

The investigation of the effects of the Ru(sub x)Cr(sub 1-x)/Ta underlayer on the microstructural and magnetic properties of CoCrPtB perpendicular films is discussed. The increase in Cr concentration from 0 percent to 40 percent led to an improvement in the c-axis anglar dispersion of (0002) CoCrPtB magnetic layers.

The influence of barrier effect of RuO2 and TiO2 on the magnetoresistance in CrO2 powder compacts is examined. The interparticle resistance and the magnetoresistance are enhanced by TiO2 due to the insulating conduction channel between the two CrO2 grains.

A general analytical coherent rotation model for AP-pinned spin valve magnetoresistance (MR) and magnetization (M) is presented. The fits reproduce the data quantitatively, and the resulting exchange strengths agree with published studies of Co/Ru/Co multilayers and ferromagnet/NiO exchange couples.

Perpendicular magnetic tunnel junctions (p-MTJs) consisting of CoPt/Ru/CoFeB/MgO/CoFeB/Pt are prepared and the tunnel magnetoresistance (TMR) of the p-MTJs has analyzed the magnetic configurations of the CoPt/Ru/CoFeB pinned layer. The studies have shown that when applied field is relatively smaller than the exchange coupling strength, the p-MTJs have shown a configurationally negative TMR as a consequence of an antiparallel alignment of the CoPt and CoFeB magnetic moments.

The article explains the various phenomenon that are present in the reversible magnetism exhibited between the antiferromagnet and ferromagnet behavior exhibited by the [[Ru.sub.2].sub.2]TCNQ charge-transfer system. The various factors affecting the magnetic properties changes of the system are also determined.

Several studies are conducted to explain the properties, as well as the magnetic hysteresis behavior exhibited by the [Ru.sub.0.25][Cr.sub.0.75][O.sub.2] thin films. The intrinsic positive exchange bias observed in a single phase epitaxial thin film ferrimagnet is also analyzed.

The various effects of Ru doping on the magnetoresistance and the magnetocaloric effects exhibited by the [Bi.sub.0.4][Ca.sub.0.6][Mn.sub.1-x][Ru.sub.x][O.sub.3] (0

The in-plane magnetic anisotropy exhibited by the boron added FeCoB films prepared on Ru underlayer is analyzed. Addition of boron is shown to lead to compression of the residual stress of the films.

The article presents complete structural, as well as magnetic characterization of the various high moment synthetic antiferromagnetic nanoparticles that are prepared by using the self-assembled stamps. These stamps are shown to be extremely beneficial in reducing the sizes of these nanoparticles.

The synthesis, properties and the magnetic structure of the [Ho.sub.2]MnRu[O.sub.7] pyrochlore oxide compound are discussed. The dc and ac magnetic susceptibilities of the compound are shown to increase significantly at higher temperatures.

The article explains the synthesis and the various transport and magnetic properties of the [Mo.sub.2.5][Ru.sub.0.5][Sb.sub.7-x][Te.sub.x] compounds. The carrier concentration is shown to highly reduce with an increase in the Te content.

The strong spin valve effect exhibited by the [Ca.sub.3][([Ru.sub.1- x][Cr.sub.x]).sub.2][O.sub.7] crystals is analyzed. The application of the spin valves in different devices is also analyzed.

The growth and the enhanced magnetization phenomena exhibited by the epitaxial SrRuO3 thin films via substrate-induced strain are analyzed. The strained films are shown to exhibit higher saturated moments, as compared to the relaxed films.