Flux trapping on multi-superconducting phase PAT12-C60Rb composite: Low-field microwave absorption study

Modulated microwave absorption measurements at 9.3 GHz were made on the low field absorption observed in the superconducting phase of Bi–Sr–Ca–Cu–O. The line intensity observed with a low modulation amplitude of 50 mOe showed a maximum between 70 K and 80 K and dropped to zero near 95 K. With a modulation amplitude of 10 Oe, an additional broad line absorption was observed above 88 K, peaking in intensity near 95 K, and disappearing above 100 K. Hysteresis, associated with flux trapping, occurred when the maximum field Hmax in a sweep cycle exceeded a critical value H*(T), which varied from about 7 Oe at 59 K to 1 Oe at 82 K. For Hmax > H*, the hysteresis splitting at first varied linearly with (Hmax – H*), later saturating at a value δHmax(T). Above 70 K, the relationship δHmax = b(T0 – T) was obeyed with T0 = 92.3 K and b· = −0.3 Oe/K for H perpendicular and b· = −0.23 Oe/K for H parallel to the c-axis.

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Low Field Microwave Absorption Study on K3C60

Advances in Superconductivity X ◽

10.1007/978-4-431-66879-4_48 ◽

1998 ◽

pp. 207-210

Author(s):

Kazushi Sugawara ◽

Nozomi Ohya ◽

Nobuhito Arai ◽

Keiji Yamamoto ◽

Haruo Hirose

Keyword(s):

Microwave Absorption ◽

Absorption Study ◽

Low Field

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Comparison of Pr-doped Ca 122 and Ca 112 Pnictides by Low-field Microwave Absorption Spectroscopy

MRS Proceedings ◽

10.1557/opl.2014.869 ◽

2014 ◽

Vol 1684 ◽

Author(s):

Austin R. Howard ◽

Jonathan D. Yuen ◽

Bing Lv ◽

Myron Salamon ◽

Ching-Wu Chu ◽

...

Keyword(s):

Magnetic Field ◽

High Temperature ◽

Microwave Absorption ◽

Absorption Spectroscopy ◽

Superconducting State ◽

Superconducting Phase ◽

Interfacial Phase ◽

Low Field ◽

Low Magnetic Field ◽

Anisotropic Magnetization

ABSTRACTPraseodymium doped CaFe2As2 (122 structure) and CaFeAs2 (112 structure) are characterized by modulated Low Magnetic Field Microwave Absorption (LFMA) spectroscopy. In both (Pr,Ca)122 and (Pr,Ca)112 structures, a strong hysteretic LFMA is found, with a TcH of ∼30 K and ∼26 K, respectively. However, in (Pr,Ca)122, measurements also show an unusual Narrow Peak (NP) LFMA signal appearing at higher temperatures, above the lower TcH superconducting state until a TcNP of 49 K. We associate this NP LFMA with interfacial superconductivity, which has been found previously by highly anisotropic magnetization measurements. Furthermore, the absence of NP in (Pr,Ca)112 correlates with the absence of an interfacial phase. These results give useful information about the microwave signature of interfacial superconductivity present in the (Pr,Ca)122 system, and may form a roadmap towards a stabilized high temperature superconducting phase in pnictides.

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Changes in Microwave Absorbtion of New High Tc Superconductors with Small Magnetic Fields

MRS Proceedings ◽

10.1557/proc-99-383 ◽

1987 ◽

Vol 99 ◽

Author(s):

K. Khachaturyan ◽

E. R. Weber ◽

P. Tejedor ◽

A. Stacy ◽

A. Portis

Keyword(s):

Magnetic Fields ◽

Superconducting Phase ◽

Superconducting Transition ◽

High Tc Superconductors ◽

High Tc ◽

Low Field ◽

Flux Trapping ◽

Field Dependent ◽

Exponential Decrease ◽

Stochastic Oscillations

ABSTRACTA low field microwave absorbtion peak was observed with an EPR spectrometer in the new superconducting oxides‥ The peak disappeared above the superconducting transition temperature after exponential decrease with temperature in the transition region. The peak was sensitive to the magnetic fields the sample has been exposed before in the superconducting phase. Magnetic field dependent stochastic oscillations of the EPR baseline are ascribed to flux trapping in Josephson junctions.

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Microwave heating effect on two Josephson-junction systems in granular PAT12C60Rb composites: low-field microwave absorption study

Physica C Superconductivity ◽

10.1016/s0921-4534(97)00099-3 ◽

1997 ◽

Vol 277 (3-4) ◽

pp. 277-284 ◽

Cited By ~ 6

Author(s):

Hirotake Kajii ◽

Hisashi Araki ◽

Anvar A. Zakhidov ◽

Kazuya Tada ◽

Kyuya Yakushi ◽

...

Keyword(s):

Josephson Junction ◽

Microwave Heating ◽

Microwave Absorption ◽

Heating Effect ◽

Absorption Study ◽

Low Field

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A comparison of the modulated microwave absorption spectra of ceramic and powdered YBa2Cu3O7-δ samples

Journal of Materials Research ◽

10.1557/jmr.1990.1813 ◽

1990 ◽

Vol 5 (9) ◽

pp. 1813-1818 ◽

Cited By ~ 3

Author(s):

R. S. Rubins ◽

Stuart L. Hutton ◽

John E. Drumheller ◽

D. Y. Jeong ◽

T. D. Black

Keyword(s):

Microwave Absorption ◽

Absorption Spectra ◽

Relative Intensity ◽

Zero Field ◽

Broad Absorption ◽

Low Field ◽

Flux Trapping ◽

Uniform Sample ◽

Glassy Sample ◽

Zero Field Cooling

Flux trapping in the 9.3 GHz modulated microwave absorption spectra observed near 4 K from ceramic and powdered ceramic specimens of two separately prepared YBa2Cu3O7-δ samples has been used to separate the intergranular and intragranular contributions to the spectra. In the denser, glassy sample, a broad absorption with a peak near 400 Oe for forward sweeps was observed with appreciable intensity after the maximum flux was trapped. This spectrum is attributed to intergranular junctions, since its relative intensity was reduced on powdering and suspending in wax. In the less dense, more uniform sample, the latter spectrum was appreciably weaker in both ceramic and powder. Both types of junction appear to contribute to the narrow low-field absorption which was observed after zero field cooling in all the samples.

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