Transport properties near the magneto/structural transition of Tb5Si2Ge2

Abstract We report high resolution measurements of the electrical resistivity (ρ, dρ/dT) and thermopower (S, dS/dT) measurements near the magnetic and structural transition of the layered Tb5Si2Ge2 compound, which are fairly close but not fully coupled. The analysis of the transport properties confirms a split magneto/structural transition, with TS ∼ 97 K and TS ∼ 107 K for the structural transition (on cooling and heating respectively; 1st-order transition). The magnetic transition occurs only at TC ∼ 112 K and without hysteresis (2nd-order transition). The magnetic critical behavior of resistivity is analyzed, obtaining an almost classical mean field exponent (α ∼ 0.59) for T > TC. For the structural phase, and below TS, we obtain a rather different exponent (α ∼ 1.06).