Physical meaning and measurement of the entropic parameter q in an inhomogeneous magnetic systems

In this paper we present a thorough analysis of two systems magnetically inhomogeneous: the manganite La$_{0.7}$Sr$_{0.3}$MnO$_3$/MgO and the amorphous alloy Cu$_{90}$Co$_{10}$. In both cases, the non-extensive statistics yield a faithful description of the magnetic behavior of the systems. In the model proposed here, the inhomogeneous magnetic system is composed by many Maxwell-Boltzmann homogeneous bits and the entropic parameter $q$ is related to the moments of the distribution of the inhomogeneous quantity. From the analysis of Scanning Tunnelling Spectroscopy (STS) images, the $q$ parameter can be directly measured.