2007/09/26 by P. Gyawali, V. Sandu, B. J. Taylor +2
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Chemistry #Condensed matter physics #Crystallography #Energy (signal processing) #Exponent #Field (mathematics) #Magnetic and transport properties of perovskites and related materials #Magnetic field #Magnetization #Order (exchange) #Physics #Physics of Superconductivity and Magnetism #Relaxation (psychology) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.77.174504
7 figures
arxiv created 2007/09/26 · openalex publication_date 2008/05/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Magnetic relaxation measurements on a series of Y_1\ensuremath-xPrxBa2Cu3O_7\ensuremath-\ensuremathδ (x=0.13, 0.34, and 0.47) single crystals were performed over a large field and temperature range in order to investigate the characteristics of the vortex matter across the second magnetization peak (SMP). The magnitude of the SMP varies nonmonotonically with Pr concentration, i.e., the irreversible magnetization normalized by its value at the onset field Hon displays a maximum for the x=0.34 single crystal. The two characteristic fields, Hon and Hsp, follow different temperature T dependences: Hon\ensuremath∝T^\ensuremathνon and Hsp\ensuremath∝[1\ensuremath-(T∕Tc)2]^\ensuremathνsp. The extracted values of the apparent activation energy U* and the creep exponent \ensuremathμ display a maximum at a field Hon<H*<Hsp. Their field dependences point toward the coexistence of both elastic and plastic creep for H>Hon. The degree of participation of each creep mechanism is determined by the charge carrier density, which controls both the elastic properties of the vortex matter and the pinning potential.