ISSN:
1572-9605
Keywords:
Hg-1201
;
synthesis
;
ampoule method
;
specific heat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract Various ceramic samples of Hg x Ba2CuO4+δ have been synthesised by the quartz ampoule method with previously prepared Ba2CuO3+y as a precursor. By tuning the mercury content x 〈 1 and controlling the synthesis of Ba2CuO3+y , we have prepared samples which show sharp superconducting transitions with different T c-values for different samples. The temperature of the onset of diamagnetism varies between 80 K and 96 K. For two samples, each with T c = 95 K, the specific heat c p(T) has been measured between 60 and 110 K with a continuous heating method. An O2-annealed sample A reveals a broad magnetic superconducting transition, whereas the transition of the as-synthesised sample B is narrow. The specific heat anomaly of the superconducting transition can clearly be identified for sample B and is broadened in applied magnetic fields. It cannot be resolved in the O2-annealed sample A, most likely because of a broad distribution of T c-values as indicated by the broad transition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022694215490
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