0000000000953977
AUTHOR
Yu. A. Boikov
Impact of granularity on transport properties of mechanically stressed La0.67Ca0.33MnO3 films
Abstract (La,Ca)MnO 3 is one of so called collosal magnetoresistive materials and it is of interest to correlate its transport properties to film growth in order to optimize its performance. Two-hundred nanometers thick (100)La 0.67 Ca 0.33 MnO 3 films were grown by laser ablation on (100)SrTiO 3 , (100)LaAlO 3 and (100)(LaAlO 3 ) 0.3 +(Sr 2 AlTaO 6 ) 0.7 substrates. The films were granular in structure with low angle boundaries between the grains. The volume of the unit cell was considerably smaller for films grown on a SrTiO 3 substrate than on LaAlO 3 . At temperatures higher than the one where the spins order, the strongest response of resistivity on temperature ρ ( T ) was measured for…
Temperature and electric field dependence of the permittivity of Ba0.9Sr0.1TiO3 films epitaxially grown on cuprate electrodes
Abstract Cuprate, high-temperature superconductors and perovskite ferroelectrics have similar crystal structures and chemical constituents and, therefore, it can be advantageous to deposit epitaxial trilayer capacitors with high-Tc electrodes and operate these at room temperature, well above the transition temperature Tc, in order to achieve a high dielectric constant, tunability, and relatively low microwave loss. Epitaxial heterostructures (200 nm)YBa2Cu3O7−δ/(600 nm)Ba0.9Sr0.1TiO3/(200 nm)YBa2Cu3O7−δ and (200 nm)NdBa2Cu3O7−δ/(600 nm)Ba0.9Sr0.1TiO3/(200 nm)NdBa2Cu3O7−δ were laser deposited on (100)LaAlO3 substrates. The relative dielectric permittivity e/e0 of Ba0.9Sr0.1TiO3 was in the ra…