Anomalies in elastic and thermal properties associated with the superconducting transition of single crystal Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>y</sub>
O -M Nes; M Castro; M Slaski; T Laegreid; K Fossheim; N Motohira; K Kitazawa; O -M Nes; Norwegian Inst. of Technol., Trondheim, Norway; M Castro; Norwegian Inst. of Technol., Trondheim, Norway; M Slaski; Norwegian Inst. of Technol., Trondheim, Norway; T Laegreid; Norwegian Inst. of Technol., Trondheim, Norway; K Fossheim; Norwegian Inst. of Technol., Trondheim, Norway; N Motohira; Norwegian Inst. of Technol., Trondheim, Norway; K Kitazawa; Norwegian Inst. of Technol., Trondheim, Norway
Журнал:
Superconductor Science and Technology
Дата:
1991-01-01
Аннотация:
The authors have measured the in-plane Young's modulus sound velocity v<sub>e</sub>(T) at kHz frequencies and the specific heat C<sub>p</sub>(T) of Bi<sub>2</sub>Sr<sub>2</sub>Ca<sub>1</sub>Cu<sub>2</sub>O<sub>y</sub> single crystals with T<sub>c</sub>=93.2 K. In the region of T<sub>c</sub> a softening is observed in v<sub>e</sub>, corresponding to a discontinuity in dlnv<sub>e</sub>/dT of 6.2 ppm/K and an indication of a change of Delta v<sub>e</sub>/v<sub>e</sub> of the order of 10 ppm. From Delta C<sub>p</sub>/T<sub>c</sub> approximately=16 mJ/(molK<sup>2</sup>) they find mod delta T<sub>c</sub>/ delta sigma <sub>i</sub> mod approximately=0.1 K/kbar and - delta <sup>2</sup>T<sub>c</sub>/ delta sigma <sub>1</sub><sup>2</sup> approximately=10<sup>-3</sup>-10<sup>-2</sup> K/kbar<sup>2</sup> (i=1,2).
192.3Кб