Correlation of local structure peculiarities and critical current density of 2G MOCVD YBCO tapes with BaZrO₃nanoinclusions

Abstract

We have studied the influence of BaZrO3 nanoinclusions on the local structure and critical current density of second-generation high temperature superconducting tapes based on YBa2Cu3O7−δ (YBCO) films. The films were made by metal–organic chemical vapor deposition (MOCVD). The crystal and local structure of the materials under study were analysed by x-ray diffraction and x-ray absorption spectroscopy (EXAFS + XANES). We have found that, being added at MOCVD process, Zr forms BaZrO3 nanoinclusions in YBCO matrix. The distance between Zr and the neighboring atoms is shorter than that one in a bulk crystalline BaZrO3, so we conclude that the nanoinclusions are in compressed state. The incorporation of 5 mol% BaZrO3 minimizes the static disorder of Cu–O bonds and maximizes their stiffness in YBCO. We show that the local structure peculiarities correlate well with the observed critical current behavior and consider this to be additional evidence in favor of small amounts of BaZrO3 nanoinclusions as efficient pinning centers.

The influence of BaSnO3 artificial pinning centres on the resistive transition of 2G high-temperature superconductor wire in magnetic field

“…Recently, SuperOx have fabricated 2G HTS wires based on GdBCO with varying concentrations of BaSnO 3 (BSO) nano-columns, using commercial production equipment, at a high HTS pulsed laser deposition (PLD) growth rate. We reported the critical current and microstructure of those wires in earlier publications [14,[19][20][21][22]. In this paper, we present for the first time the study of the B-T phase diagram of those samples under a magnetic field up to 9 T with different orientation.…”

“…The experiments were carried out on four 2G HTS wire samples with varied concentrations of BSO. The fabrication of these samples and their microstructure and transport superconducting properties were described earlier [14,[19][20][21][22]; here we outline the key relevant features. The wires were made using the standard SuperOx commercial production technology and equipment [23,24].…”

Nanosized Pinning Centers in the Rare Earth-Barium-Copper-Oxide Thin-Film Superconductors

“…The resulting pinning centers are subsequently formed by chemical reaction, as in the case of Y(thd)3, Ba(thd)2*tetraglyme, Cu(thd)2, Zr(thd)4 as precursors in the form of the mixture of the precursor powders. The resulting YBCO film contained BaZrO 3 nano-inclusions [118]. The problem with the introduction of the pinning material in the form of the precursor can be that it is difficult to obtain phase-oriented dispersed pinning as needed.…”

Увеличение Критического Тока Сверхпроводящих Композитов При Имплантации Ионов Железа

“…В частности, в работах [12,13] было показано, что наночастицы BaZrO 3 имеют высокие перспективы как кандидаты в инертные центры пиннинга. Исследования по созданию искусственных центров пиннинга на основе нанодобавок проводились для ВТСП-пленок, полученных различными методами: импульсного лазерного напыления [14,15,16], металлоорганического осаждения жидких прекурсоров [17,18], осаждения металлорганических соединений из газообразной фазы [10,11,[19][20][21][22][23]. Наряду с монодобавками, рассматривался способ создания структур с комбинацией точечных и колончатых дефектов [24].…”

“…В результате исследований было показано, что включения BaZrO 3 в тонких пленках ВТСП собираются в коррелированные структуры в виде столбчатых дефектов, которые особенно хорошо работают как центры пиннинга в перпендикулярном магнитном поле [15,[19][20][21]. Аналогичные работы были проделаны для BaSnO 3 .…”