The possibility of detection of small absorption in HTS thin films by means of the highly sensitive OFC magnetometer

Citation
Sg. Gevorgyan et al., The possibility of detection of small absorption in HTS thin films by means of the highly sensitive OFC magnetometer, PHYSICA C, 363(2), 2001, pp. 113-118
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICA C
ISSN journal
0921-4534 → ACNP
Volume
363
Issue
2
Year of publication
2001
Pages
113 - 118
Database
ISI
SICI code
0921-4534(20011101)363:2<113:TPODOS>2.0.ZU;2-U
Abstract
We have essentially widened the capabilities of the open-flat coil-based tu nnel diode oscillator technique (OFC magnetometer) for simultaneous tests o f magnetic penetration depth, A, of rf magnetic field and for detection of small changes of absorption inside the thin plate-like HTS materials. The u pdated method is based on simultaneous detection of the inductance and Q-fa ctor value changes of the unusual flat (single-layer open-faced geometry) c oil-based MHz-range resonator, which finally leads to the resonant frequenc y and amplitude changes of the oscillator. Our technique enables detecting the changes similar to 10(-12) H of HTS film's magnetic inductance (the cha nges similar to1-3 Angstrom of lambda). It detects also the changes similar to 10(-9) W of testing field's power absorption by the film, originated fr om the variation of its internal flux distribution (due to vortex flow duri ng the suppression of superconductivity by external magnetic field). It can operate in wide ranges of temperature and magnetic field and measure in wi de dynamic ranges of the testing parameters. We present the test results of the 0.2 mum thick and a few millimeter in diameter disk- and ring-shaped Y BaCuO films illustrating wide capabilities of the updated OFC magnetometer to study weakly expressed peculiarities of superconductive state related, i n particular, with the insignificantly small absorption at vortex motion. ( C) 2001 Elsevier Science B.V. All rights reserved.