ISSN:
1063-7834
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract We have studied the growth characteristics, structure, and parameters of the epitaxial heterostructures (001)NdBa2Cu3O7−δ /(100)SrTiO3/(001)NdBa2Cu3O7−δ grown by laser ablation on a (100)LaAlO3 substrate with a thin (∼2 nm) YBa2Cu3O7−δ intermediate layer. The use of an YBa2Cu3O7−δ intermediate layer promotes layered growth of the (200 nm) NdBa2Cu3O7−δ layer, whose free-surface roughness is 4–5 nm. The resistance of the NdBa2Cu3O7−δ layers began to fall off abruptly at T=92 K, and at T≈87 K it vanished completely. The critical current density in the NdBa2Cu3O7−δ layers at T=76 K exceeded 106 cm2 A/cm2. The dielectric constant of the (400 nm) SrTiO3 layer sandwiched between the NdBa2Cu3O7−δ epitaxial layers grew by roughly threefold as the temperature was lowered in the interval 300–4.2 K. When a bias voltage of ±2.5V was applied to the NdBa2Cu3O7−δ electrodes, the relative dielectric constant of the (400 nm) SrTiO3 intermediate layer fell from 1150 to 400 (T=32 K, f=100 kHz). The conductivity of the SrTiO3 intermediate layer in the direction perpendicular to the substrate plane increased with temperature and the electric field strength.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1134/1.1130783
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