YBa₂Cu₃O_7−δ/Y₂Ba₄CuMO_ysingle grain nanocomposite superconductors with high critical current densities

Abstract

Nanocomposite Y-Ba-Cu-O superconductors containing a wide range of Y 2 Ba 4 CuMO y (Y-2411), where M = Nb, Ta, Mo, W, Zr, Hf, Ru, Ag, Sb, Sn and Bi, embedded in the YBa 2 Cu 3 O 7−δ matrix, have been fabricated successfully. The Y-2411 phase typically has dimensions in the range 20-50 nm and it is observed to form effective flux pinning sites even at higher magnetic fields. A direct correlation between the Y 2 Ba 4 CuMO y phase inclusion content in the YBa 2 Cu 3 O 7−δ matrix and increased magnetic flux pinning has been observed. The critical current density increases by an order of magnitude for a nanocomposite compared to that of Y-123 without inclusions.

Enhanced self-field critical current density of nano-composite YBa 2 Cu 3 O 7 thin films grown by pulsed-laser deposition

“…Bulk Y-123 superconductors containing insulating M-2411 nano-particles show strongly enhanced magnetic flux pinning and critical current densities over a range of temperatures and applied magnetic fields [17].…”

Bulk Superconducting Nano-Composites With High Critical Currents

“…The microstructures of other Y Ba CuMO phases have been reported in [7]- [12]. Y Ba CuNbO phase inclusions were observed to undergo negligible ripening at high temperature during processing and were shown to retain their nano-scale dimensions (20-40 nm), in stark contrast to the behavior of the Y-211 phase [11]. Although Y-2411 phase inclusions were dispersed at the nano-scale level, as shown in Fig.…”

Characterization of nano-composite M-2411/Y-123 thin films by electron backscatter diffraction and in-field critical current measurements

“…For M-2411/Y-123 bulk superconductors, a linear increase of J c with M-2411 content is observed [4]. Table 1 summarizes the critical temperature T c , the self-field J c at T = 77 K and 65 K, and the pinning force density f p = J c (B, T) × B measured at T = 65 K and B = 1 T (applied field oriented parallel to caxis of layer, H || c) of the HTS thin film samples.…”

“…The ceramic targets used consisted of Y-123 as matrix material and of Y 2 Ba 4 MCuO x (M-2411, M = Ag and Nb) nano-particles embedded in the matrix. The M-2411 phase has a double-perovskite cubic structure and is chemically stable up to a high temperature (melting point above 1700 °C) [4,5]. The content of secondary phase in ceramic targets was varied from 0 to 5 mol %.…”