Magneto-electric and thermo-electric transport properties in bulk Ge₂Sb₂Te₅

We report on electrical conductivity (C) and Seebeck coefficient (S) in bulk Ge2Sb2Te5, a phase change material (PCM) from room temperature down to ~500 mK under a range of applied magnetic fields (B< 20 T). The zero field resistivity data is adequately described by the Block- Gruneisen formula. In addition zero field (B=0) C and S is observed to follow a generalized Noritheim-Gorter like scaling behavior. Which may indicate that two independent types of scattering processes is dominant in controlling the transport rate in this material. A positive magnetoresistance, i.e., DC resistance is increased when a magnetic field is applied. However, the field dependence is neither quadratic nor linear in B. Instead the observed rate is sublinear in B, in other words DR(B)/R(0) is a concave function of B.