Cu NQR in high Tc superconductor Y1−xPrxBa2Cu3O7

✍ Scribed by T. Ohno; K. Koyama; H. Yasuoka

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 172 KB
• Volume: 199-200
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)91803-1

✦ Synopsis

The NQR spectra and the nuclear spin-lattice relaxation rate 1/T~ associated with the Cu(2) sites in Y~ -~Pr~BazCu307 with x = 0.1 and 0.2 have been investigated. The spectrum of Yo.sPro.2Ba2Cu30~ at 4.2 K is found to be broadened in the high-frequency side, and the half-width becomes two times of that for pure YBa2Cu30,. It is also noted that several distinct lines contribute to the spectrum with increasing Pr concentration. These spectral features are quite different from the case of oxygen-depleted YBa2Cu307_~, in spite of the similar behavior in the decrease of 7",. The temperature dependence of 1/TI T for x = 0.1 shows a maximum around 106 K. This temperature is much higher than Tc = 86 K, indicating that the Pr doping induces the pseudo-spin-gap behavior. From the Curie-Weiss fit of I/T~ TI Th it is concluded that the Pr doping is considered to enhance the 2D AF spin ttuctuations from the decrease of the Weiss temperature.