Electrical properties of epitaxial junctions betweenNb:SrTiO3and optimally doped, underdoped, and Zn-doped

Abstract

Epitaxial thin films of optimally doped, underdoped, and Zn-doped YBa 2 Cu 3 O 7−␦ ͑YBCO͒ were grown on single crystal ͑001͒ Nb: SrTiO 3 substrates by pulsed laser deposition ͑PLD͒ and the electrical properties of the corresponding interface junctions were examined. The growth conditions were optimized in each case to get the appropriate crystalline quality of the films as well as the desired normal state and superconducting properties. The films or heterointerfaces were characterized by x-ray diffraction, Rutherford backscattering ͑RBS͒ ion channeling spectrometry in normal and oxygen resonance modes, magnetic susceptibility, four probe in-plane resistivity, and the temperature dependent current-voltage ͑I-V͒ characteristics. Nonlinear I-V curves ͑forward and reverse͒ were obtained in all the cases, revealing some characteristic differences and interesting temperature evolution. These data, when analyzed within the framework of a standard description of transport across the metal-semiconductor ͑Schottky͒ interface, suggest lateral intrinsic nanoscale electrical inhomogeneity in the system. Also as compared to the case of optimally doped YBCO a small but definitive lowering of the effective Schottky barrier height ⌽ B is observed for junctions based on oxygen underdoped and Zn-doped YBCO.

Superconducting gap induced barrier enhancement in a BiFeO3-based heterostructure

“…Interfacial couplings in such heterostructures can potentially present a wide range of emergent phenomena. 16 Indeed, a variety of fascinating properties has been evidenced in YBCO-based junctions, [17][18][19][20][21] rendering the BFO/YBCO heterostructure an excellent candidate in the search for novel properties in low dimensions.…”

Interface-dependent rectifying TbMnO3-based heterojunctions

“…[9][10][11][12] Furthermore, TMO exhibits distinct magnetic phases in various temperature regimes: the collinear spin order of Mn ions sets in at a Neel temperature T N of 41 K; the ferroelectric phase emerges in the bc-spiral spin state below 28 K, and concurrently the magnetic and the polarization vectors orientate along the b and the c axis, respectively; finally, a phase transition at about 7 K appears as a result of the magnetic ordering of the Tb sublattice. 4 As the first step towards the oxide electronics, a wide range of transition metal oxides are exploited in various device concepts, such as Schottky-like junctions, [13][14][15][16] field-effect transistors, 17,18 a Email: tomwu@ntu.edu.sg; rmwang@buaa.edu.cn 2158-3226/2011/1(4)/042129/11 C Author(s) 2011 1, 042129-1 and p-n junctions, [19][20][21][22][23] which are the building blocks in conventional semiconductor electronics. 24 Among them, two-terminal junctions are often considered as the most fundamental one due to their ubiquitous presence in many devices with higher complexity.…”

Multiferroic oxide thin films and heterostructures

“…Indeed, a variety of fascinating properties have been evidenced in YBCO-based junctions. [171][172][173][174][175] Epitaxial growth of BFO/YBCO heterostructure can be realized due to the compatible lattice structure in the two materials with a lattice mismatch of $3%. Interfacial couplings in such heterostructures may drastically upset the delicate balance of the competing interactions among charges, spins, orbitals, and lattice, which can potentially present a wide range of emergent phenomena.…”