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Elastic and thermal properties of Au/Ni superlattices have been investigated by x‐ray diffraction on a synchrotron radiation source at the Photon Factory. An elastic response of [Au(10 A)/Ni(10 A)]50 to hydrostatic pressure generated by a diamond anvil cell has been measured in the layer‐stacking direction. Its compressibility obtained from the pressure dependence of its superlattice period (Λ vs P) shows an anomalously small value compared with either bulk Au or Ni metal. Linear thermal expansions has also been measured by a similar method (Λ vs T). A significant anisotropic behavior between the layer‐stacking and in‐plane direction was found in both [Au(10 A)/Ni(10 A)]50 and [Au(4 A)/Ni(4 A)]210.

An NiFe (200A)/Cu (200A)/NiFe (50A) trilayer film of submicron width was prepared, and the noncoupled-type giant magnetoresistance (GMR) effect was investigated. Magnetization reversal in a single submicron-sized magnetic wire was sensitively detected through a sudden jump in resistance due to antiparallel alignment of two NiFe layers. It was demonstrated that an artificially introduced neck in the wire acts as an obstacle to magnetic domain wall propagation.

PbSe/SnSe superlattice, phase transition, high pressure, SR x-ray diffraction) Synchrotron x-ray diffraction experiments have revealed successive phase transitions in epitaxially-grown PbSe/SnSe superlattices. The transition pressures from the low-pressre cubic B1- to the high-pressure orthorhombic B16-type structures are observed to vary systematically depending upon thickness of the PbSe layer. For example, a [PbSe(36A)/SnSe(12A)]19, with the B1 structure in both layers stabilized in its asgrown state, undergoes the [B1/B1]-to-[B1/B16] and [B1/B16]-to-[B16/B16] structural transitions at 1.9 and 3.8GPa, respectively. This result is in contrast to their bulk data that the B1-to-B16 transition takes place at 5.3GPa in PbSe while the B16 phase is stable in SnSe at atmospheric pressure.

A new class of corrugated multilayers has been grown on silicon substrates which have (111) faceted grooves etched on their surface. These structures can be probed by conventional means with current at an angle to the plane of layers (CAP) as well as CIP. This angle is fixed by: the depth to width ratio of the grooves (which determines the angle θ), and the angle φ of the current probes with respect to the grooves. We have prepared multilayers of [Co(12 A) Cu(t)NiFe(12 A) Cu(t)]y with t=58 and 116 A, and y=167 and 91 repeats, respectively; and have varied φ from 0 and 90° while θ is held fixed at 54.7°. We find the data is very well fit to the theoretical expression for CAP resistivity in terms of the more conventional CIP and CPP resistivities. From measurements of the CIP and CAP–MR’s on these corrugated multilayers we are able to predict the CPP–MR for these structures.

Mossbauer experiments were made utilizing Co57or Fe57as a microprobe for studying the magnetic properties of ferromagnetic metal surfaces. For the emission spectroscopy, carrier-free Co57atoms were electrodeposited on a surface of bulk iron. The absorption spectroscopy was applied to a sample whose surface was selectively enriched with Fe57. In both cases, the spectra at 4.2 K showed that all iron atoms in the surface are ferromagnetic, but the reduced hyperfine field suggests a partial decrease of the local magnetic moment.

Multilayered films are prepared by the alternate deposition of Mn and Sb in ultrahigh vacuum. On deposition, Mn atoms react with Sb atoms to form a ferromagnetic compound MnSb at the interface. The MnSb layers grow epitaxially on thick Sb layers. By utilizing this epitaxy, ultrathin (less than 10A) MnSb layers are sandwiched between thick (50A) Sb layers. The resulting superlattice films are ferromagnetic even when each MnSb layer thickness is less than 5A.

Superlattice films consisting of ferromagnetic Fe and antiferromagnetic Mn were prepared by ultra-high-vacuum evaporation. The alternate stacking of BCC Fe (110) and alpha -Mn (110) lattice planes when the superlattice periods are in the range from 40 to 80 AA and the Fe and Mn layer thicknesses are equal was confirmed by X-ray diffraction. The films have fibrous textures which are composed of coherent grains of approximate dimensions of 100 AA in the film plane and 200 AA along the growth direction. The distributions in the growth orientation are within 10 degrees . Mossbauer spectra indicate that alloy layers are formed at the interface regions and that the degree of atomic intermixing is rather extensive at the interfaces, where Fe atoms are deposited on Mn layers. The thicknesses of the alloy layers are in the region of 10 AA. When Fe layers thinner than 15 AA are sandwiched by Mn layers, the structure is changed significantly because of alloying. The Mossbauer spectra show unresolved magnetic splitting, with the magnetic hyperfine field widely distributed in the range from 0 to 200 kOe (100 kOe on average). The magnetisation curve strongly depends on the external field and also on the thermal history. The properties of Fe-rich layers are similar to those of the Fe-Mn amorphous alloy and the magnetic behaviour of the multilayers is interpreted as mictomagnetism.

Fe-Mg superlattices are synthesized by UHV deposition and the magnetic properties are studied from Mossbauer spectroscopy, polarized neutron and magnetization measurements. An Fe monolayer sandwiched in between Mg layers is ferromagnetic and the easy direction is along the film normal.

57Fe Mossbauer experiments were performed to study the magnetic properties of an iron surface which was selectively enriched by vacuum deposition of a thin (≈5 A) 57Fe layer and subsequently protected by a thick Cu film. The spectra at 4.2 K show that all Fe atoms near the surface are ferromagnetic, but the reduced hyperfine field suggests a partial decrease of the local magnetic moment.

Magnetic properties of glassy oxide films which exhibit ferromagnetism and ferroelectricity simultaneously above room temperature prepared by reactive rf sputtering are presented. Nominal film composition is the solid solution compound system expressed by (1−x)BiFeO3‐x ABO3, x=0–1 where ABO3 denotes ferro‐ (antiferro‐) electric perovskites, such as BaTiO3, PbTiO3, and PbZrO3. Spontaneous magnetization 4πMs for as‐deposited films is small behaving paramagnetically and does not show the compositional dependence. After annealing at temperatures of 600–700 °C in either air or PbO atmosphere, considerably large 4πMs exceeding 1 kG appears at the solid solution composition. All samples with large 4πMs are x‐ray amorphous and a rapid decrease in 4πMs takes place after annealing at higher temperatures (≳800 °C), where still unidentified crystallites are precipitated. Mossbauer absorption spectra were done to understand the origin of ferromagnetism. Besides pronounced magnetic (and/or dielectric) properties, these...