The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 12 3 2019 11 26 Effects of the sintering temperature on the flux-pinning mechanism and the activation energy of malic-acid doped MgB2 Effects of the sintering temperature on the flux-pinning mechanism and the activation energy of malic-acid doped MgB2 264 264 991 FA SR Ghorbani M Bashi MSA Hossain J Peleckis Journal Article 2019 11 26   The flux-pinning mechanism and activation energy of 10 wt % malic acid-doped MgB2 were investigated by measuring of the critical current density and resistivity as a function of magnetic field and temperature. A crossover field, Bsb, was observed from the single vortex to the small vortex bundle pinning regime. For the sintered sample, the temperature dependence of Bsb(T) at low temperature is in good agreement with the δℓ pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation. The activation energy was decreased by increasing the magnetic field and increased by increasing sintering temperature.   The flux-pinning mechanism and activation energy of 10 wt % malic acid-doped MgB2 were investigated by measuring of the critical current density and resistivity as a function of magnetic field and temperature. A crossover field, Bsb, was observed from the single vortex to the small vortex bundle pinning regime. For the sintered sample, the temperature dependence of Bsb(T) at low temperature is in good agreement with the δℓ pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation. The activation energy was decreased by increasing the magnetic field and increased by increasing sintering temperature. https://ijpr.iut.ac.ir/article_991_692f93be8c7a41525c0baf2076aecfb4.pdf