TY - JOUR
T1 - Harmonic susceptibilities and pinning properties of MgB2 bulk superconductors
AU - Senatore, Carmine
AU - Polichetti, Massimiliano
AU - Zola, Danilo
AU - Di Matteo, Tiziana
AU - Giunchi, Giovanni
AU - Pace, Sandro
PY - 2003/5
Y1 - 2003/5
N2 - The fundamental and third harmonics of the ac magnetic susceptibility have been studied on MgB2 bulk superconductors, obtained by reactive liquid infiltration. In particular, measurements performed as a function of temperature, dc magnetic field, ac field amplitude and frequency have been compared with susceptibility curves obtained by means of numerical simulations of the non-linear diffusion equation for the magnetic field. The experimental frequency dependence of the χ1″(T) and |χ3|(T) peak amplitude cannot be explained by frequency dependent critical state models. On the contrary, we have shown that the measured curves are correctly derived using a diffusion coefficient dominated by a creep process within the framework of the vortex glass approach.
AB - The fundamental and third harmonics of the ac magnetic susceptibility have been studied on MgB2 bulk superconductors, obtained by reactive liquid infiltration. In particular, measurements performed as a function of temperature, dc magnetic field, ac field amplitude and frequency have been compared with susceptibility curves obtained by means of numerical simulations of the non-linear diffusion equation for the magnetic field. The experimental frequency dependence of the χ1″(T) and |χ3|(T) peak amplitude cannot be explained by frequency dependent critical state models. On the contrary, we have shown that the measured curves are correctly derived using a diffusion coefficient dominated by a creep process within the framework of the vortex glass approach.
KW - Ac susceptibility
KW - Flux dynamics
KW - MgB
UR - http://www.scopus.com/inward/record.url?scp=0038188557&partnerID=8YFLogxK
U2 - 10.1016/S0921-4534(02)02706-5
DO - 10.1016/S0921-4534(02)02706-5
M3 - Conference article
SN - 0921-4534
VL - 388-389
SP - 161
EP - 162
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
T2 - proceedings of the 23rd international conference on low temper
Y2 - 20 August 2002 through 27 August 2002
ER -