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The superconductor-ferromagnet proximity effect describes the fast decay of a spin-singlet supercurrent originating from the superconductor upon entering the neighboring ferrornagnet. After placing a conical magnet (holmium) at the interface between the two, we detected a long-ranged supercurrent in the ferromagnetic layer. The long-range effect required particular thicknesses of the spiral magneticall|y ordered holmium, consistent with spin-triplet proximity theory. This enabled control of the electron pairing symmetry by tuning the degree of magnetic inhomogeneity through the thicknesses of the holmium injectors. 10.1126/science.1189246

The HoMn[O.sub.3] films with different crystalline structure are synthesized on various substrates by pulsed laser deposition. The crystalline orientation of HoMn[O.sub.3] films is strongly dependent on the substrate. It is found that the pure hexagonal and orthorhombic HoMn[O.sub.3] films can be grown on the [Y.sub.2][O.sub.3] : Zr[O.sub.2] (111) and LaAl[O.sub.3] (110) substrates, respectively. Based on the results of temperature dependent magnetizations M(T), it is observed that the magnetic behavior of the hexagonal HoMn[O.sub.3] film is different from that of the orthorhombic HoMn[O.sub.3] film. We expect that this systematic study will serve as a guidance to make high quality HoMn[O.sub.3] films with different structures. And, these films can be eventually utilized for the applications of multiferroic devices. Index Terms--Hexagonal, HoMn[O.sub.3], manganites, multiferroics, perovskite.

The low-temperature magnetization with epitaxial hexagonal HoMn[O.sub.3] films and single crystal is examined and compared. It is shown that a ferroelectric switching at room temperature is shown despite the leakage with a film resistivity of about [10.sup.9] [omega] cm.

Dielectric measurements are used for characterizing magnetic phase transitions in the doped ferroelectric oxides [Ho.sub.1-x][Y.sub.x]Mn[O.sub.3] (x=0.4). The magnetic field anisotropy is very important in understanding the magnetic and electric phase competition in the diluted 4f system by the nonmagnetic yttrium (Y) ion and the dielectric response is a very good probe for analyzing the spin-spin interactions in diluted [Ho.sub.1-x][Y.sub.x]Mn[O.sub.3].

Metamagnetic transitions in single-crystal rare-earth nickel borocarbide Ho[Ni.sub.2][B.sub.2]C and Er[Ni.sub.2][B.sub.2]C at T=1.9 K is studied with a Quantum Design torque magnetometer. Torque measurements of the Er borocarbide clearly show that the sequence of metamagnetic transitions with increasing field depends on the angular direction of the magnetic field relative to the easy axis.

Second harmonic generation (SHG) was used for examining the phase diagram of hexagonal HoMnO3 in the magnetic-field/temperature plane. A tetracritical point in the phase diagram is observed as a result of independent occurrence of in-plane or interplane recording of Mn spins at the phase boundaries.

The article explains the magnetic, as well as the magnetothermodynamic properties of [Ho.sub.5][Si.sub.4] compounds. The heat capacity of the material is shown to be completely dependent on the temperature.

Several experimental studies are conducted to explain the magnetic properties and the magnetocaloric effects observed in the [Ho.sub.6- x][Er.sub.x]Mn[Bi.sub.2] compounds. The compounds are shown to exhibit sharp decline in magnetization near their magnetic ordering temperature.

Several Stern-Gerlach deflection measurements are conducted to explain the different magnetic moments , as well as electric polarizabilities of the free Tb, Ho and Tm clusters. The properties of these clusters are shown to be completely dependent on their size.

The article explains the synthesis, as well as the characterization of the spectrally tunable magnetic nanoparticles that are specially designed for the various distribution/recollection applications. The robust properties and the chemical stability of the nanoparticles are also explained.

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.

Numerous analyses are conducted to explain the magnetic phase diagram and the magnetic and magnetoelectric properties of the [Ho.sub.0.25][Nd.sub.0.75][Fe.sub.3][([BO.sub.3]).sub.4] compounds. The spontaneous polarization of the compounds is shown to increase sharply at low temperatures.

The magnetic, dielectric, and ferroelectric behaviors are measured to understand the multiferroic behaviors of rare-earth titanate cubic pyrochlore [Ho.sub.2][Ti.sub.2][O.sub.7] ceramics prepared by the standard solid state reaction. The ferroelectric transition with a small polarization identified upon the gradual spin ordering sequence with decreasing temperature and the origin of ferroelectricity and its possible correlation with the spin order at low temperature is discussed.

Monte Carlo simulations are presented for Ho magnetic thin films and the system is described by a Heisenberg model with easy-plane single-ion anisotropy and seven coupling constants. The progressive reduction in the number of layers has not implied sudden helical order suppression at low temperature but rather as a consequence of surface effects, a gradual passage to a fanlike order, accompanied by the helix distortion is observed.

The magnetic and electronic properties of a single-crystal Ho[B.sub.4] are examined. The isothermal magnetization with an applied magnetic field perpendicular to the c-axis has showed two metamagneticlike transitions and a rapid change in the temperature and the field-dependent resistivity is intimately correlated with magnetic transitions.

[Nd.sub.3][Cu.sub.4][Sn.sub.4], [Nd.sub.3][Ag.sub.4][Sn.sub.4], and [Ho.sub.3][Cu.sub.4][Sn.sub.4] are analyzed by using [super 119]Sn Mossbauer spectroscopy. The ordering of the Ho 2d sublattice in [Ho.sub.3][Cu.sub.4][Sn.sub.4] is observed at 8.2(1) K and also some residual magnetic splitting up to 10.5(2) K is seen.

The effect of holmium (Ho) doping in films of [Ni.sub.0.8][Fe.sub.0.2] (NiFe) is examined and the ferromagnetic resonance (FMR) is measured. The studies have shown that Ho concentrations as small as 2% can increase intrinsic damping in NiFe while minimizing change in other practical magnetic properties.

The compound [Ho.sub.2][Mn.sub.3][Si.sub.5] has displayed multiple transitions and its paramagnetic Curie temperature is shown to be small but positive. The various transitions in magnetization data are due to the ordering of rare earth and Mn moments and the magnetization at 2K in applied fields of up to 7 T has linear field dependence, which has shown dominant antiferromagnetic interactions in the system.

The magnetic susceptibility, heat capacity and electrical resistivity in single crystalline samples of [Ho.sub.2]Co[Ga.sub.8] intermetallic compound are measured. The low temperature magnetic properties have shown the effects of tetragonal crystalline electrical field and the Ruderman-Kittel-Kasuya-Yosid interactions and the results are compared with the evolution of the low-T magnetic properties of structurally related series of rare-earth tetragonal 2-1-8 and 1-1-5 compounds.

The effect of the local structure distortion on the magnetic transition in La doped Ho[Mn.sub.2][O.sub.5] is examined. The ferromagnetic (FM) transition is attributed to the formation of magnetic clusters in a host paramagnetic matrix.

Hexagonal HoMn[O.sub.3] is considered as a frustrated antiferromagnet ferroelectric with a rich magnetic phase diagram consisting of multiple temperature- and field-dependent phases. Neutron-diffraction measurements in a magnetic field reveal new intermediate-field phases at low temperatures.

The circularly polarized x rays were used for imaging the spiral magnetic domain structure in a single crystal of Ho metal. A characteristic length scale on the order of 50 mum is exhibited by the images of the chiral domain structure exhibit.

The magnetic properties of the trigonal B12 cluster compounds HoB(sub 17) CN and ErB(sub 17)CN are investigated. The spin glass-like behavior was observed, which may be caused due to disorder from partial occupancy of the rare earth atomic sites and also possible frustration of magnetic interactions.

Ac-susceptibility, which is performed on an ensemble of highly diluted Ho(super 3+) ions in a single crystal of LiYF4, at temperatures above the bottleneck regime is discussed. It shows a very rich behavior in which various quantum relaxation mechanisms are clearly identified.

The magnetic entropy change at low temperature of the HoNi2 polycrystalline compound is presented. Magnetic and calorimetric measurements agree with the theoretical model, which assumes that the crystalline electric field plays an important role at low temperatures.

Structure and magnetic properties of the Ho-substituted [Nd(sub 1-x)Ho(sub x)](Sub 3)Fe(sub 23-y)Co(sub 6)V(sub y) compounds is discussed. It can be seen that the B(sub a) increases first from x=0 to 0.5, going through a maximum at x=0.5, then decreases with further increasing Ho content.

The temperature dependence of the Mossbauer spectra of Ho2Fe17 and Ho2Fe17D(sub 3.8) is described. The variations with rare-earth of the weighted average isomer shifts and hyperfine fields in R2Fe17, R2Fe17H(sub x) and R2Fe17N3 are explained in terms of the lanthanide contraction and lattice expansion upon insertion of hydrogen, or deuterium or nitrogen and the axial and basal magnetic anisotropy.