The peak effect in single-phase B1 MoCy encapsulated in multiwall carbon nanocages

✍ Scribed by Yositaka Yosida

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 330 KB
• Volume: 468
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2008.09.008

✦ Synopsis

Isothermal magnetization hysteretic loops in nanocrystalline single-phase B1 MoC y encapsulated in multiwall carbon nanocages are studied. The initial magnetization curves show the sharp peak near zero field H pen and the broad peak at H p (>H pen ). The peak field H pen increases exponentially with temperature T; H pen (T/T c ) = H pen (0)exp[ÀT/T o ] with values of H pen (0) = 20 kOe and T 0 = 1.4 K. On the other hand, the peak field H p shifts linearly with decreasing T. At low temperatures, the sharp peak and the broad peak merge into a single peak. All of the features of the hysteretic loops have been found in a less anisotropic high-T c compound of Nd 1.85 Ce 0.15 Cu 2 O 8+d . The value of T o is consistent with the model that two-dimensional point vortices are thermally activated near the lateral surface of a layered superconductor.