skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Growth and characterization of laser-deposited superconducting Bi--Sr--Ca--Cu--O thin films

Journal Article · · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)
DOI:https://doi.org/10.1116/1.578553· OSTI ID:6238625
;  [1]
  1. Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Superconducting Bi--Sr--Ca--Cu--O thin films with thickness 400--3500 A have been deposited on (100) MgO and (100) LaAlO[sub 3] by a pulsed excimer XeCl laser ([lambda]=308 nm, [tau]=20 ns, and energy density=4--5 J/cm[sup 2]). The oxygen pressure during deposition and the substrate temperature are in the range of 0.1--100 mTorr and 350--750 [degree]C, respectively. The as-deposited films were annealed either inside ([ital in] [ital situ]) or outside ([ital ex] [ital situ]) the deposition chamber to improve the crystallinity and the superconducting transition of the films. The formation of 2212 and 2223 phases was controlled by tailoring the deposition and annealing parameters. The corresponding transition temperatures ([ital T][sub [ital c]]'s) of these phases in the [ital ex] [ital situ] films measured by zero-field cooled diamagnetic transition at 10 Oe are 80 and 110 K; however, the [ital in] [ital situ] mirrorlike shiny films with 2223 phase only exhibit [ital T][sub [ital c]]=81 K (or 98 K in an ac field of 0.1 Oe at 125 Hz). These films were also characterized by scanning electron microscopy, transmission electron microscopy, superconducting quantum interference device magnetometer, and ac susceptometer to study their morphology, microstructure, and magnetic properties. The critical magnetization current density ([ital J][sub [ital c]]) of the [ital ex] [ital situ] films is of the order of 10[sup 7]--10[sup 8] and 10[sup 5]--10[sup 6] A/cm[sup 2] for [ital H][perpendicular][ital c] axis and [ital H][parallel][ital c] axis, respectively, at 7 K up to 5 T. [ital J][sub [ital c]] of the [ital in] [ital situ] films is two orders of magnitude lower than that of the [ital ex] [ital situ] films, and further enhancement of [ital J][sub [ital c]] appears promising if better crystallinity of the [ital in] [ital situ] films can be achieved.

OSTI ID:
6238625
Journal Information:
Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Vol. 11:4; ISSN 0734-2101
Country of Publication:
United States
Language:
English