Crystal structure and electromagnetic responses of tetragonal GdAlGe

Abstract

The ternary rare-earth aluminum germanide GdAlGe with tetragonal structure is systematically studied by x-ray diffraction, magnetic and electric measurements. The magnetic and electric properties of GdAlGe are strongly related to its special magnetic structure formed by magnetic Gd3 isosceles triangles △s. The GdAlGe orders ferromagnetically at 21 K due to the exchanging interaction of Gd3 △ ↑ – △ ↑ Gd3. The mechanism of magnetic transport originates from the slip scattering induced by Stoner spin fluctuation in the magnetic ordering region and the spin wave scattering induced by the thermal photon excitation and phonon scattering in the paramagnetic region. The positive magnetoresistance is observed in GdAlGe, which might be due to the disordered magnetic scatter induced by magnetic anisotropy in GdAlGe.