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The magnetic-force microscopy technique is employed to explain the various magnetic antiphase domains observed in the Co/Ru/Co trilayers. The thickness of the trilayers is shown to exhibit an inverse relationship with the magnetic field.

Several different techniques are employed to explain the magnetization and the electron behavior exhibited by the different [R.sub.2][Ru.sub.3][Ga.sub.9] (R = Ce and U) compounds. The resistivity is shown to be inversely proportional to the temperature of the system.

The article explains the complex magnetic order and spin chirality exhibited by the lattices of the Ba[Mn.sub.2.49][Ru.sub.3.51][O.sub.11] and Ba[Fe.sub.3.26][Ti.sub.2.74][O.sub.11] systems. The generation of the topological Hall effect by the scalar chirality is also analyzed.

Magnetization versus magnetic field measurements at several temperatures were used to analyze the IrMn/Co/NM/[Ni.sub.81][Fe.sub.19] spin valves, with the nonmagnetic (NM) spacers of Ru and Cu grown by sputtering. The analyses results provided quantitative values of both contributions and revealed that the oscillatory coupling mechanism dominates in the system with Ru spacer, while the Neel coupling mechanism dominates for the Cu spacer.

The effect of a 4d ion ([Ru.sup.3+]) substitution on structural disorder and magnetic ordering in the cyanide-bridged molecular magnets, [Ru.sub.x][Ni.sub.3-3x/2][[Cr[(CN).sub.6].sub.2] z[H.sub.2]O is examined. The studies have helped in designing new molecular magnets by controlling vacancies, leading to a tuning of the intertwined structural and magnetic properties.

Systematic studies on the crystallographic growth, magnetic properties, microstructure, and recording performance of CoCrPt-Si[O.sub.2] perpendicular magnetic recording media on RuCoCr type of intermediate layers are presented. The effectiveness of the RuCoCr-oxide type of intermediate layers toward grain size reduction and in improving the performance of perpendicular magnetic recording media are also discussed.

The magnetization profile of Ir in a MnIr/CoFe exchange bias system is examined by x-ray resonant magnetic reflectivity at Ir [L.sub.3] absorption edge. A stacked multilayer sample of MgO/[[Ru/[Mn.sub.75][Ir.sub.25]/[Co.sub.70][Fe.sub.30]].sub.15]/Ru has shown that the Ir is magnetized at the MnIr/CoFe interface.

Heusler alloy [Co.sub.2]FeAl is used as ferromagnetic layers in [Co.sub.2]FeAl/Ru/[Co.sub.2]FeAl synthetic antiferromagnet structures. The studies have shown that the as-deposited [Co.sub.2]FeAl film is in the B2 phase and Heusler alloys are used for preparing synthetic antiferromagnetic and it is possible to make 'all-Heusler' spin valves or magnetic tunneling junctions with between magnetic switching properties and high magnetoresistance.

A study is conducted to examine the effect of hydrostatic pressure (P) and external magnetic field on the c-axis resistivity ([P.sub.c]) and in-plane ac susceptibility ([chi.sub.ab]) of [La.sub.1.2][Sr.sub.1.8][([Mn.sub.1-y][Ru.sub.y]).sub.2][O.sub.7] (y=0 and 0.075) single crystals. The nature of P dependence of [[chi].sub.ab] of Ru-doped sample is observed to change significantly around 1.5 GPa in the ferromagnetic state.

[Co.sub.90][Fe.sub.10] films with an in-plane uniaxial magnetic anisotropy are grown on an obliquely sputtered thin Ru underlayer. The switching characteristics of the nanoelements prepared from the films by e-beam lithography are examined, where no degradation of magnetic anisotropy is found after the annealing and lithographical process.

Multiferroic ([Bi.sub.0.90][La.sub.0.10])([Fe.sub.0.95][Mn.sub.0.05])[O.sub.3] (BLFMO) thin films are deposited on SrRu[O.sub.3] (SRO) buffered Pt/Ti[O.sub.2]/Si[O.sub.2]/Si(100) substrates with variable buffer layer thicknesses by using off-axis radio frequency sputtering. The BLFMO thin film has displayed the increased magnetic behavior as compared to pure BFO thin films because of the canting of antiferromagnetically ordered spins.

The microstructure and local chemistry of Ta/Ru/Ta/CoFeB/MgO/CoFeB/Ta/Ru magnetic tunnel junctions are examined with different values of tunneling magnetoresistance (TMR) as a result of annealing at different temperatures. The degradation in TMR of the samples annealed at 650 [degree]C has resulted from the loss of bcc-CoFe (001) texture in the bottom CoFeB electrode because of the pronounced Ta diffusion into the CoFe/MgO/CoFe layers.

The structural, magnetization, heat capacity and electrical resistivity measurements are carried out on a new ruthenate compound [La.sub.3.5][Ru.sub.4][O.sub.13]. The antiferromagnetic (AFM) order is associated with the AFM coupling of Ru ions of the quasi-2-dimensional layers and the resistivity and magnetic data have shown that the quasi-2D substructure has shown semiconducting behavior, while a metallic behavior is expected for the 1D slabs.

X-ray diffraction, ferromagnetic resonance (FMR) and x-ray magnetic circular dichroism (XMCD) are used for studying Co/Ru superlattices grown by magnetron sputtering. The XMCD measurements have provided Co spin magnetic moments lower than the bulk Co value, which has confirmed the presence of a Co magnetic region with a lower local effective magnetization attributed to the Co/Ru interfaces.

The temperature dependence of the extraordinary Hall effect (EHE) in ultrathin films of the itinerant ferromagnet SrRu[O.sub.3] is dependence. The resistivity of the film has varied significantly with their thickness, whereas the EHE at low temperatures is determined solely by resistivity.

Anomalous magnetic behavior is found in the polycrystalline Heusler alloy system [Ru.sub.2][Mn.sub.1-x][Fe.sub.x]Ge. The magnetoresistance (MR) effect is described by a model in which antiferromagnetic and ferromagnetic domains are coexisting.

The structural, magnetic, and electronic transport properties of [([Sr.sub.0.9][Ca.sub.0.1]).sub.3][Ru.sub.2][O.sub.7] are studied by using single crystals grown by a floating-zone technique. The results have shown that lattice, spin and charge degrees of freedom are coupled in this system and the band width narrowing caused by the structure distortion is responsible for the increase in the ferromagnetic correlations and the change of transport properties.

The systematic dc and ac magnetic susceptibility measurements performed on Ru[Sr.sub.2][Eu.sub.1.5][Ce.sub.0.5][Cu.sub.2][O.sub.10-[delta]] (Ru1222) have shown a paramagnetic to ferromagnetic transition around 95 K. The temperature dependence of the second and third harmonic ac susceptibilities has confirmed the coexistence of a cluster of glass state and ferromagnetic order in the Ru1222 system.

Polycrystalline samples of [Ru.sub.1-x][Nb.sub.x][Sr.sub.2][Eu.sub.1.4][Ce.sub.0.6][Cu.sub.2][O.sub.10-[delta]] are prepared by conventional solid state reaction by using stoichiometric amounts of high purity Ru[O.sub.2], [Nb.sub.2][O.sub.5], SrC[O.sub.3], [Eu.sub.2][O.sub.3], Ce[O.sub.2] and CuO powders. The critical temperatures, including the onset, intergrain and intragrain transition and [T.sub.R=0] transition temperatures, have depended on the Nb content, microstructure and applied magnetic field.

Ru/FeCoB/CoPtCr-Si[O.sub.2] films are prepared as perpendicular magnetic recording media with crystalline soft magnetic underlayer (SUL). The studies have shown that the application of a crystalline SUL has promoted the reduction in the intermediate layer thickness.

A concept is proposed for the nonmagnetic intermediate layer (NML) in order to realize a recording layer of small, highly c-plane oriented grains with no intergranular exchange coupling. The fast Fourier transform analysis of plan-view transmission electron microscopy lattice images of Ru layers has disclosed that hexagonal close packed Ru grains in a c-plane oriented film has combined with each other due to the disappearance of low-angle tilt boundaries.

A soft magnetic intermediate layer is described for partially replacing the Ru intermediate layer in order to improve the recording efficiency in perpendicular recording media. The multilayer film has displayed the hcp orientation with dome morphology for facilitating the growth of the top magnetic storage layer as well as soft magnetic properties.

CoRuCr-oxide based intermediate layers are introduced as a replacement for pure Ru-based intermediate layers in perpendicular recording media, as they provide better C-axis orientation than the Ru intermediate layers. Grain size and grain size distribution are reduced with CoRuCr-oxide intermediate layers and magnetic properties have shown that the CoRuCr-oxide intermediate layers are good candidates for perpendicular recording media.

FePt-X (X =C, Ti[O.sub.2], [Ta.sub.2][O.sub.5]) nanocomposite films are deposited on MgO/CrRu/glass substrates by magnetron cosputtering. [Ta.sub.2][O.sub.5] doping has showed better grain isolation than the others and the out-of-plane coercivities of FePt-Ti[O.sub.2] and FePt-[Ta.sub.2][O.sub.5] films are shown to be 7.5 and 8.8 kOe, respectively.

The MgO-based magnetic tunnel junctions (MTJs) with a synthetic ferromagnetlike structure are prepared, where CoFe is coupled magnetically with CoCrPt through the thin Ru layer. The transport properties with a magnetic field applied perpendicular to the film plane have disclosed a tunnel magnetoresistance ratio of about 6% at room temperature.

The magnetic structure of Cr[O.sub.2]-Ru[O.sub2] interfaces and multilayer structures are studied. The first-principles calculations have shown that Cr[O.sub.2]-Ru[O.sub.2] layered structures are designed to provide the desired magnetic ordering between Cr[O.sub.2] layers given sufficient control over the composition and roughness of the deposited material.

The role played by the thicknesses of the capping layers in tunneling magnetoresistance (TMR) and the effect of the capping layers above the CoFeB/MgO/CoFeB are studied. The thicknesses of the capping Ta and Ru layers have a major impact on the TMR and the stress or strain applied onto the MgO barrier by these capping layers are shown to be responsible.

The exchange-coupling fields of CeFe/Ru/CoFe synthetic antiferromagnetic (SyAF) structures with a Ru underlayer and capping layer before and after annealing are examined. The results have shown that distribution is caused by the existence of the AF coupling of various coupling fields due to annealing and a large exchange-coupling field after high temperature annealing is obtained by suppressing the distribution of the exchange coupling in the SyAF structure.

Interlayer coupling is analyzed in a series of perpendicular antiferromagnetically coupled multilayers with asymmetric structures Pd/[[Pd/Co].sub.5]/Ru/Co/[Pd/Co].sub.3]/Pd/Si substrate. An antiferrostripe domain without a ferromagnetic shift is observed at the as-deposited state and stray-field induced ferromagnetic domains have appeared in multilayers with weak antiferromagnetic coupling.

The changes in the resistivity anisotropy of epitaxial SrRu[O.sub.3] films due to induced magnetization in the paramagnetic state are explored by using the planar Hall effect. The studies have shown that the effect of the induced magnetization on the in-plane anisotropy is angular dependent, and have provided a full description of this behavior at 160 K for induced magnetization in the (001) plane.

The antiferromagnetic state seen in [Lu.sub.2][Fe.sub.17] at elevated temperatures is stabilized down to the ground state in [([Lu.sub.0.8][Ce.sub.0.2]).sub.2][Fe.sub.17] and [Lu.sub.2][Fe.sub.16.5][Ru.sub.0.5]. The pressure and substitution effects are understood in terms of exchange interaction varying with changes in the lattice parameter c for [([Lu.sub.0.8][Ce.sub.0.2]).sub.2][Fe.sub.17], while for [Lu.sub.2][Fe.sub.16.5][Ru.sub.0.5], the change in magnetic structure has occurred due to the weakening of the positive exchange interaction as a result of the reduction in the Fe magnetic moments.

FeCoB layers prepared on Ru underlayer have a high saturation magnetization [M.sub.s] and a high in-plane magnetic anisotropy field [H.sub.k] and the effects of their preparation conditions are examined. The accumulation of anisotropic stress in the film caused by the oblique incidences of depositing atoms with high energy is one of the key effects to attain high anisotropy field and it is succeeded to prepare the Ru/FeCoB films with high [H.sub.k] of 500 Oe.

The magnetic anisotropic properties and the spin wave relaxation in trilayer films of CoFe/PtMn/CoFe grown on the seed layer Ru or NiFeCr with CoFe compositions being Co-16 at. % Fe is examined. A significant linewidth broadening is caused by the overlap of the surface and the uniform spin wave excitations and the ferromagnetic resonance lines have shown a strong dependence of the surface anisotropy contribution of free energy in trilayer films.

The change in the switching fields of the CoCrPt-Si[O.sub.2] recording layer resulting from the presence of the high-pressure Ru layer is examined. The increase in the magnetic anisotropy and the decrease in the intergranular exchange coupling of the CoCrPt grains due to the presence of the high-pressure Ru layer are shown to be the major reasons for the changes in the switching fields of the CoCrPt-Si[O.sub.2] recording layer.

A comparative study is performed between the magnetotransport (MT) and the magnetocaloric effect (MCE) data in ordered state as well as in the paramagnetic state to gain insight into the complex MT behavior of Gd[Ru.sub.2][Si.sub.2] compound. The results obtained from the comparative study of MCE and MT could be applied to understand the complex MT behavior of the magnetic material and derive magnetic phase diagram of magnetic compound.

A miscut SrTi[O.sub.3] (STO) (001) substrate was used to create a stable twin-free CaHf[O.sub.3] perovskite oxide thin film with large orthorhombic distortion on a STO (001) substrate. The method could also be applied to stabilize many other oxides that have large lattice mismatches with STO substrate and large orthorhombic distortion.

Electrical conductivity, magnetic susceptibility and point contact Andreev reflection (PCAR) studies are used for analyzing bulk, polycrystalline Sr[Ru.sub.1-x][(TM).sub.x][O.sub.3] (TM = Cr, Mn, Ti) and Sr[Ru.sub.0.92][O.sub.3] with a high degree of disorder. The spin polarization is unchanged for both Sr[Ru.sub.0.94][Ti.sub.0.06][O.sub.3] and Sr[Ru.sub.0.9][Mn.sub.0.1][O.sub.3], while it is changed for Sr[Ru.sub.0.9][Cr.sub.0.1][O.sub.3].

A new method for synthesis and characterization of the first pentanuclear extended metal atom chains (EMACs) of the second-row transition metals, [[Ru.sub.5][([[mu].sub.5]-tpda).sub.4][X.sub.2]] where ([tpda.sup.2-] = tripyridyldiamido dianion, X = Cl and NCS) is reported. The detailed studies provide insight into the spectroscopic, magnetic properties, electrochemical redox states, and electrical conductance.

A detailed study report for paramagnetic diruthenium tetracarboxylates of differing complexity such as unsolvated monomers, bis-adducts, and oligomers is reported. The results from provide insights into the factors determining the polymeric strand conformation as a key parameter and the influence of equatorial aliphatic chains.

The magnetism of Ca[Ru.sub.1-x][Mn.sub.x][O.sub.3] is studied by using magnetic Compton scattering measurements for polycrystalline specimens at 10 K under 2.5 T by using a synchrotron-radiation x-ray. The results have shown that a sort of ferrimagnetism is established in the Ca[Ru.sub.1-x][Mn.sub.x][O.sub.3] system.

The exchange-dominated surface and bulk spin-wave modes are studied in a single period of CoFe/PtMn/CoFe trilayer films grown on a seed layer of Ru with CoFe film compositions. The SWR spectra are explained in terms of dynamic surface spin pinning by including an effective surface anisotropy field.

The role of magnetic phase transitions on magnetocaloric effect in polycrystalline Sr[Ru.sub.1-x][Mn.sub.x][O.sub.3] (0