In applications of superconducting devices, the crystalline texture of high-quality YBa 2 Cu 3 O 7−x thin films is of primary importance. The preferred orientation of the films can be essentially controlled by means of the substrate temperature, T s . In order to study the dependence of the film texture on different T s , a series of films were deposited on YSZ substrates by the on-axis pulsed-laser ablation technique. The substrate temperature was varied from 600 • C to 800 • C while the rest of the growth parameters remained the same. Various analytical techniques, including x-ray diffraction, scanning electron microscopy, micro-Raman spectroscopy and the four-point probe method, were applied to characterize the films. At around T s = 700 • C, the best films with the smoothest surface morphology, lowest FWHM of the rocking curve and highest in-plane texture were obtained. The resultant J c in excess of 1 × 10 6 A cm −2 at 77 K and T c around 91 K were also achieved at this temperature.

The influence of substrate temperatures on the structure, morphology, magnetic properties, and surface composition of MnSb films prepared by hot-wall epitaxy are analyzed. All the films are found to be single phase with nickel arsenide (NiAs) crystal structure. X-ray photoelectron spectroscopy study on the core levels reveals that the surface oxidation of the films is not very much enhanced with increasing substrate temperature except for a variation in the concentration of Sb2O3 and MnO2 near the surface-air interface. The decrease in saturation magnetization for the films is attributed to an increase in the manganese oxide content as substrate temperature increases. It is also observed that preferential Mn segregation from the grains to the grain boundaries will reduce the magnetic coupling between grains and thus increase coercivity and decrease coercivity squareness.

The tnatcrn;tl R: s pLtsnLt COIICL'lltration Lttio or salbuumol was recently reported to be signific:tntly ltighn than the cord r:ttio after :tdministration of ;t 'iinglc ltttLtVL'nou> dose ofLtlTtllate to women prior to Caesarian section IKI. This fi11ding was ;tttributcd to etLttttioselcctive pbccntal-t(rral tneubolisttt resulting in !own concentrations of the (R)-enantiontL'I" (cutomn) in the fre urnury excretloll 1:11.

Heavy metal fluoride glass ZBLAN, with molar composition ZrF4(53)–BaF2(20)–LaF3(4)–AlF3(3)–NaF(20), was studied in vacuum at high temperatures up to 480°C by Raman spectroscopy. The vitreous glass was found to crystallize at 330°C, most probably to β‐BaZrF6 crystallites. High‐temperature experiments in air were also carried out and ZrO2 was formed at the surface of the sample. Doping by SiO2 increases the crystallization temperature by 25°C for experiments performed in air, while PbO2 dopants are found to react with the host. © 1997 John Wiley & Sons, Ltd.

MnSb epitaxial layers were grown on GaAs (100) substrates by hot-wall epitaxy and the structural, morphology, and magnetic properties of the layers were examined. In this study, three films of different nominal film thicknesses were fabricated. All the films are found to be well-interconnected with low intergrain resistance values being measured. It is observed that the thinnest film has grains elongated along GaAs [011] and the grains in the other two thicker films exhibit two orthogonal domains. The above microstructures of the films have a marked impact on the easy magnetization axis. The easy magnetization axis of the thinnest film is found to be along that of the elongation direction of the grains and that for the thickest film is along GaAs [011̄] (along the [12̄.0] axis of MnSb). The largest measured values for coercivity, remanent magnetization, and squareness ratio of the three films are found in the thinnest film, and the thickest film has the highest saturation magnetization. Finally, the angular variation of coercivity curves indicate that the magnetization reversal mechanism of the three films is an incoherent rotation type, i.e., non-Stoner–Wohlfarth type.