JOURNAL OF LOW TEMPERATURE PHYSICS, vol.152, pp.63-70, 2008 (SCI-Expanded)
Total magnetostriction in the superconducting state for high T(c) superconductors has been separated into critical state and paramagnetic components in terms of a H(x) dependent magnetic flux density. We show that the paramagnetic part is chi(2+chi) < H(x)(2)>, where chi is paramagnetic susceptibility. We have reproduced successfully Delta L/L-H(a) curves measured by de la Fuente et al. (Phys. C 244:214, ), in which they clearly observed coexistence of superconductivity and paramagnetism, employing the concepts presented in this work.