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The effect of isovalent chemical substitution of [Eu.sup.3+] into the [Tb.sup.3+] sites on the magnetic and electrical properties of ([Tb.sub.1-x][Eu.sub.x])Mn[O.sub.3] (0 less than equal to x less than equal to 1.0) system is examined. The results have shown that the increase in the Eu content has increased both the tolerance factor and Mn-O bond distance, leading to the reduction in the octahedral distortion and Jahn-Teller (JT) effect.

Exchange-induced spin polarization in the magnetic semiconductor EuS at room temperature studied by X-ray magnetic-circular-dichroism measurements is reported. An alignment of the Eu moments is denoted at the interface as spin polarization yielding a net EuS Magnetization and this turns Co/EuS multilayers into promising material for spin injection applications.

The high- and low-temperature crystal structures of Sm3OsO7, Eu3OsO7 and Gd3OsO7, as well as the magnetic properties of these oxides are reported. The results show that Sm3OsO7 and Eu3OsO7 exhibit complex magnetic behavior below about 50 K, and Gd3OsO7 shows a ferromagnetic-like order at 34 K applied fields of less than 10 kG.

A synthesis of EuO was carried out through the thermal reduction of Eu2O3 by a stoichiometric quantity of metallic Eu. EuO undergoes a second-order phase transformation at ~69 k from the ferromagnetic to the paramagnetic state on heating as indicated by the heat capacity and magnetic measurements.

The magnetization, thermal conductivity and thermopower of polycrystalline samples of [Nd.sub.1-x][Eu.sub.x]Ni[O.sub.3] compounds are measured as a function of temperature and external magnetic field. The results have shown a coexistence of ordered and disordered phases below the temperature [T.sub.N] and that an applied magnetic field is suitable for increasing the thermoelectric properties close to [T.sub.S].

Powder x-ray diffraction and magnetic measurements are used for investigating the crystal structure and magnetic properties of Eu[Mn.sub.x][Ga.sub.3-x] intermetallics. The ferromagnetic order is found to be very weak and sensitive to the applied field, which is interpreted as the Mn spin state change induced by charge balance at low field.

Multiferroic single crystals R[Mn.sub.2][O.sub.5] (R = Bi, Eu and Dy) are analyzed by using the temperature dependent Raman scattering study. The anomalous phonon behaviors in bending and stretching modes are consistent with the spin-phonon coupling in a scenario of strong magnetic correlations.

Superconducting quantum interference device magnetometry was used for examining the semiconducting EuS/PbS/EuS trilayers displaying antiferromagnetic coupling. There exists strong dependence of the interlayer coupling energy on the temperature or magnetization as indicated by the simulations of the magnetic moment versus the temperature.

Co/EuS multilayer samples deposited in a molecular beam epitaxy system are examined with varying numbers of layers and different-single layer thickness. Antiferromagnetic coupling is not present at room temperature due to the small magneto-optic signals of the EuS layers.

The structural and magnetic properties of EuS spin filters in combination with PbS and magnetic metallic electrodes are examined. Improved magnetic and transport properties are observed in the barrier layer after growing EuS films at 200 degrees C and annealing it at the elevated temperatures of 430 degrees C.

Electrical, magnetic and Mossbauer measurements are performed on [La.sub.0.67-x][Eu.sub.x][Ca.sub.0.33]Mn[O.sub.3] in order to study different grain size materials. The combined effect of chemical pressure induced due to the additional rare earth doping and smaller grain size has led to a more stable AFM phase where no such hysteresis is observed in field cooled cooling and warming cycles of magnetization measurements.

Several studies are conducted to analyze the magnetic properties, magnetocaloric effect and the refrigerant capacity that is observed in the various Sr-doped [Eu.sub.8][Ga.sub.16][Ge.sub.30] type-I clathrates. These compounds are shown to be extremely beneficial for numerous cryogenic magnetic refrigeration applications.

The article explains the formation, electronic structure and the various magnetic and transport properties of the different Eu[Mn.sub.2] films. The resistivity of these films is shown to be completely dependent on the temperature.

Electronic flexibility and colossal magnetoresistance effects are discovered in the perovskite oxynitrides EuW[O.sub.1+x][N.sub.2-x] and ammonolysis of [Eu.sub.2][W.sub.2][O.sub.9] has produced scheelite-type intermediates EuW[O.sub.4-y][N.sub.y] with a small degree of nitride substitution. Both the Eu and W oxidation states and the hole/electron doping are tuned by varying the O/N ratio, EuW[O.sub.1+x][N.sub.2-x] phases order ferromagnetically at 12 K and colossal magnetoresistances (CMR) are seen in the least doped sample.

The article explains the synthesis, structures and the properties of the various 3,12)-connected porous lanthanide-organic frameworks that are shown to be based on [Ln.sub.4][O.sub.4] clusters. The magnetic structure and properties of the clusters are also discussed.

The intrinsic ferromagnetic behavior in Co-doped ZnO diluted magnetic semiconductors (DMSs) induced by Eu codoping is reported. The observation of multiplet structures for the localized Co 3d states indicated that the codoped Eu plays a critical role in facilitating the Co substitution of Zn which results in intrinsic ferromagnetism.

The displacement currents are studied for both different starting conditions and polarizing electric fields along with the field dependent magnetodielectric effect in [Eu.sub.0.8][Y.sub.0.2]Mn[O.sub.3] ceramics. The magnetic field dependence of the complex dielectric constant has shown that the magnetodielectric effect is dependent on the phase it is being considered and has provided evidence for the ferroelectric character of the AFM-2 phase.

An alternating gradient magnetometer was used to measure the electrical and magnetic properties of the GaN thin films codoped with Eu and Si, grown on sapphire by solid source molecular beam epitaxy technique. The films with higher conductivity showed an anomalous Hall effect and an increase up to approximately nine times in saturation magnetization at low-to-moderate Si doping levels while all film samples showed increase in saturation magnetization under illumination at 371 nm.

Several room temperature x-ray power diffraction measurements are conducted to explain the preparation, as well as the magnetothermal behavior of the mixed valence [Eu.sub.3][O.sub.4] compound. The presence of different magnetic transitions at different temperatures is discussed.

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.

A sample of [super 33]S-enriched EuS is prepared and the nuclear magnetic resonance (NMR) and its temperature dependence is measured in order to resolve the conflicting reports on weak NMR [super 33]S signals in unenriched EuS. The [super 33]S spin-echo measurements are shown to be consistent with a power law, but are not with a [T.sup.2] dependence.

Anisotropic x-ray magnetic linear dichroism (AXMLD) has provided a novel element-, site-, shell- and symmetry-selective methods for analyzing the magnetic anisotropy induced by a crystalline electric field. The weak [Eu.sup.2+] [M.sub.4,5] AXMLD observed in EuO(001) has shown that the Eu 4f states are not rotationally invariant and might contribute weakly to the magnetic anisotropy of EuO.

The multiferroic properties of [Bi.sub.1-x][Eu.sub.x]Fe[O.sub.3] ceramics prepared by conventional solid state reaction method are studied. The substitution of Eu in place of Bi has increased the magnetization at room temperature.

The ultrathin EuO films grown as a stepped wedge on Si/Si[O.sub.2]/Cr/Cu and capped with Y/Al are characterized by using x-ray magnetic circular dichroism (XMCD) at the europium [M.sub.5] and copper [L.sub.3] edges. The high quality and consistent magnetic properties of these films are confirmed by superconducting quantum interference device magnetometry, disclosing a constant saturation moment independent of film thickness.

The polarization of the tunnel conductance of spin-selective ferromagnetic insulators is modeled and has provided a generalized concept of polarization including both the effects of electrode and barrier polarization. These tunnel barriers have a large effect on the tunneling polarization, both positively and negatively, depending on the material parameters and the model is applied to spin-filter devices containing the spin filter material EuO.

The thickness dependence of the magnetic and transport properties of thin EuO films is examined. The ferromagnetic phase transition has shown a dependence of the critical temperature [T.sub.c] with decreasing EuO film thickness, which is attributed to the interface layers that has played a major role by reducing the number of average magnetic neighbors.

Neutron scattering experiments using a two-dimensional detector are used for measuring a nuclear Bragg peak and its six surrounding magnetic satellites in (110)europium film. The thermal history of the film has dramatic consequences on the magnetic configurations, correlated with lattice clamping effects persisting above the magnetic ordering temperature.

Domain-acoustic echo (DAE) signals in polycrystalline ferrite [Co.sub.0.01][Mn.sub.0.05][Cu.sub.0.18][Ni.sub.0.2][Mg.sub.0.72][Fe.sub.0.6][O.sub.4], europium garnet and iron borate are comparatively studied. The DAE in the europium garnet is characterized by intensive signals and has the lowest threshold for radio-frequency pulse powers and suppressing magnetic field values.

A comparative first principles study is carried out for EuLi[H.sub.3] (ELH) and EuTi[O.sub.3] (ETO) by using the generalized gradient approximation +U approach. The difference in magnetic behavior and magnitude of the nearest neighbors exchange interaction of both the compounds are related to the difference in their respective electronic structure near the Fermi level.

The perovskite oxynitrides EuM[O.sub.2]N (M = Nb, Ta) are prepared and their coupled colossal magneto-resistive and capacitive effects are studied. The results have shown an excellent potential for large magneto-responses in materials like EuNb[O.sub.2]N, which has combined the large [Eu.sup.2+] spin and the off-center instability of [Nb.sup.5+] enhanced by bonding to nitride.

The synthesis, structures, as well as the magnetic properties of the face-sharing heterodinuclear Ni(II)-Ln(III) (Ln = Eu, Gd, Tb, Dy) complexes are discussed. The magnetic susceptibility and magnetization of these complexes are shown to be highly temperature- and field-dependent.

The synthesis, characterization, and magneto-optical properties of europium selenide (EuSe) nanoparticles are reported. The magneto-optical properties of EuSe show improvement because of confined electronic states and enhanced optical transition cross-section.

The temperature dependent magnetism of EuS/Co films has disclosed two EuS ordering temperatures [T.sub.C]. The enhanced [T.sub.C] is the result of EuS interface moments exchanged coupled to Co moments in an antiparallel configuration.

The dielectric, magnetic and magnetotransport properties of Sr doped [RE.sub.2-x][Sr.sub.x]Co[O.sub.4] (RE=Pr or Eu, x=0.25-1.5) are studied. The temperature dependence of resistivity has shown that both systems change from semiconductive to metallic with Sr doping and the magnetoresistance is found for the EuSrCo[Co.sub.4] compound.

The magnetic and electronic transport properties of [Eu.sub.1-x][La.sub.x][B.sub.6] are examined. Temperature-dependent magnetization of [Eu.sub.1-x][La.sub.x][B.sub.6] has displayed antiferromagnetic ground state with transition temperature [T.sub.m] = 5 K and thermal hysteresis below [T.sub.m] between field-cooled and zero-field-cooled modes with the magnetic field of H = 0.1 kOe.

A novel flux growth method is used for preparing polycrystalline samples of the ternary interlanthanide chalcogenide system Eu[Ln.sub.2][X.sub.4] (X=S and Se) for many heavy lanthanides (Ln). The crystal structure and magnetic properties of Eu[Ln.sub.2][X.sub.4] are studied at low temperatures.

High resolution and grazing incidence x-ray scattering experiments are performed to examine the magnetostructural coupling in (110) europium film. The grazing incidence is used for showing that the structural characteristics are nonhomogeneous with the film depth, the dominant structural domain being different in the top and bottom parts of the film.

The depth-dependent magnetic structure of a EuO magnetic tunnel junction having a Gd electrode, Si/Cu/EuO/Gd/Al, is analyzed by using polarized neutron reflectometry. The differences of the structural and magnetic behavior of the Gd layer relative to bulk in vital in optimizing the tunnel magnetoresistance in these samples.

The synthesis and magnetic characterizations of highly crystalline lanthanum strontium manganite (LaSrMn[O.sub.2]) and Eu-doped [Y.sub.2][O.sub.3] and their composites are described. The manganites and their composites with luminescent nanoparticles are very useful for biomedical applications.

Rare-earth ions such as [Eu.sup.3+] with magnetic dipole transitions are used as spectroscopic tools for probing and exploring effects of optical magnetism in plasmonic nanostructures. The systems based on Eu[(N[O.sub.3]).sub.3].[Bpy.sub.2] has shown high quantum yield of emission, high sensitivity to relative changes in the optical magnetic field distribution and are considered as a promising candidate for such applications.

The maganetic and electronic properties of [Eu.sub.14]Mn[Sb.sub.11] and [Yb.sub.14]Mn[Sb.sub11] zintl compounds are studied from the temperature dependence of their antimony-121 Mossbauer spectra. The Mossbauer spectra of [Eu.sub.14]Mn[Sb.sub.11] are more complex due to magnetic transition of both manganese and Eu ions as compared to only manganese ion of [Yb.sub.14]Mn[Sb.sub11].

The temperature dependence of resistivities of [Eu.sub.0.58][Sr.sub.0.42]Mn[O.sub.3] at different magnetic fields under ambient pressure and 1GPa is presented. The findings suggest that the antiferromagnetic insulating phase could be transformed into the ferromagnetic metallic phase by either magnetic field or pressure.

The changes of magnetic properties and phase transition in EuO films grown on a MgO(100) substrate are studied as a function of temperature. The temperature driven changes in the electronic and magnetic properties of EuO films on a MgO(100) substrate is elucidated.