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Studies of cuprate/manganate bilayers deposited onto SrTiO3 substrates by laser ablation are reported. It is argued that there is no significant electronic interaction involving spin ordering.

Reporting the suppression of the critical current of thin film layers by altering the magnetization of a ferromagnetic overlayer is discussed. It shows that the results are consistent with a value for the spin diffusion length which is small compared with the average domain size in the unmagentized state of the LCMO.

Research was conducted to examine the influence of the substrate on growth and magnetoresistance of La0.7Ca0.3Mn0z thin films grown by magnetron sputtering. Magnetoresistance of polycrystalline resulted in two contributions, a low-field magnetoresistance ratio (MR) and a high-field MR whose dependence on temperature are markedly different. The low-field MR is related to the magnetization process and can be attributed to scattering processes in domain walls or to tunneling of polarized charge carriers between the grains of the polycrystalline films.

Formulae for calculating the resonance frequency and microwave losses in high-temperature superconducting (HTS) periodic coplanar waveguide resonators prepared on ferroelectric/dielectric substrates are obtained and numerically analyzed.

The low-field magnetoresistance (MR) effect in polycrystalline thin films at T

Byline: L. Mechin, Ch. Simon, R.A. Chakalov The surface magnetic domain patterns of a La2/3Sr1/3MnO3 film grown on a LSAT (001) substrate, where LSAT stands for (LaAlO3)0.3(Sr2AlTaO6)0.7, were observed by magnetic force microscopy (MFM) as a function of the temperature in the 300-360 K range at its remanent state. Magnetic stripe domains showing an up and down magnetic configuration were observed, thus indicating the existence of a small out-of-plane magnetisation component. The domain size was in the order of 300 nm and did not vary with temperature. However the magnetic contrast in the MFM phase images decreased as the temperature increased and vanished as it approached the Curie temperature of the film. MFM measurements were compared with magnetisation vs. temperature curves measured by superconducting quantum interference device magnetometer.

Looks a tan experiment which investigated the influence which off-axis radio frequency magnetron sputtering had on the growth of La0.7Ca0.3MnOz thin films. Detailed information on the experiment; What the results showed.

Examines the magnetoresistance and the magnetization of single-crystalline and polycrystalline films of La0.7M0.3MnO3-...(M=Ca, Pb) in the ferromagnetic state. Influence of oxygen deficiency on the magnetotransport of the films; Why charge transport in polycrystalline manganites were affected by grain boundaries; Examination of whether magnetoresistance behavior in low magnetic fields is compatible with spin-polarized tunneling.

Ca- and Zn-subsituted Y1-xCaxBa2(Cu1-yZny)3O7-δ (x=0, 0.05 and y=0, 0.02, 0.04, 0.05) thin films were grown on SrTiO3 (1 0 0) substrates using the pulsed laser deposition (PLD) technique. Effects of various growth parameters on the quality of the film were studied via X-ray diffraction (XRD), atomic force microscopy (AFM), and in-plane resistivity, ρab(T), measurements. The deposition temperature and oxygen partial pressure were gradually increased to 820 °C and 1.20 mbar, respectively. Films grown under these conditions exhibited good c-axis orientation (primarily limited by the grain size) and low values of the extrapolated residual resistivity, ρ(0), at zero temperature. The planar hole content, p, was determined from the room-temperature thermopower, S[290 K], measurements and the effects of oxygen annealing were also studied. Fully oxygenated samples were found to be overdoped with p∼0.195. The superconducting transition temperature Tc(p), and ρ(T,p) showed the expected systematic variations with changing Zn content. [Copyright &y& Elsevier]

We report resistance/temperature, conductance/voltage and voltage/magnetic field measurements in a range of junctions between collosal magnetoresistive materials and the high temperature superconductor YBa2Cu3O7-δ. We identify two forms of behaviour. In one form the resistance of the junction falls monotonically with decreasing temperature and is associated with zero bias conductance peaks. In the other form the resistance rises below some characteristic temperature T*. In this latter case there is no zero bias conductance peak, but there are peaks in the voltage/magnetic field behaviour below T*. We tentatively associate T* with the pseudogap temperature. [Copyright &y& Elsevier]

Abstract: Magnetotransport properties of thin films of La1− x Ca x MnO3 (; 0.51) deposited on LaAlO3 and SrTiO3 substrates were investigated. Compressively strained La0.7Ca0.3MnO3 layers reveal semiconducting behaviour and charge ordered insulating (COI) phase which melts to ferromagnetic metallic (FMM) above a certain magnetic field, accompanied by a significant hysteresis. The La0.49Ca0.51MnO3 samples possess stable COI state. Variable range Hopping mechanism well describes the conductance in zero magnetic field. Magnetotransport properties of strained thin films are consistent with the phase segregation model, i.e. with the coexistance and competition of COI and FMM phases. [Copyright &y& Elsevier]

Abstract: Thin films of La1-xCaxMnO3 (, 0.51) have been deposited on LaAlO3 (LAO) and SrTiO3 (STO) substrates by magnetron sputtering (MS) and pulsed laser deposition (PLD). Lattice strain induced by substrate misfit results in drastic change of transport and magnetic properties. The very thin sample (thickness of ∼15nm) with deposited by MS on LAO substrate reveals compressive strained layer and semiconducting behaviour in zero magnetic field. Application of strong magnetic field of 7.5T leads to metallic behaviour and metal–insulator transition at a temperature about a bulk value of 250K. A sharp transition to a low-resistive state above a certain magnetic field is found at T<50K and associated with a significant hysteresis. Such a behaviour is similar to the phenomenon of melting of a charge ordered state by magnetic field that is first-order transition. Samples with substitution rate of deposited by PLD on LAO and STO substrates showed different behaviour due to variable strain of manganite layer. Magnetotransport properties of strained thin films are discussed due to the coexistence of ferromagnetic metallic and charge-ordered insulating phases and percolation processes. [Copyright &y& Elsevier]