Schottky specific heat of the lightly Mn-substituted electron-doped SrTiO

Okuda, Tetsuji*; Kajimoto, Ryoichi  ; Noda, Masaaki*; Kuwahara, Hideki*

Large changes in the low-temperature specific heat (low-) by applying magnetic fields up to 9 Tesla were found in the lightly Mn-substituted electron-doped perovskites SrLaTiO. The changes in the low- are qualitatively well explained by the Schottky specific heat () of localized spins of the Mn 3d electrons in weak internal magnetic fields via itinerant electrons. According to the analysis by using the conventional model, the doped Mn ions are apparently not Mn ( = 3/2) ions, but are Jahn-Teller active Mn ( = 2) ions or mixtures of Mn and Mn ions. However, the actual numbers of localized spins estimated from are about 30% smaller than the expected values. Part of the localized spins of the Mn 3d electrons may disappear due to Kondo coupling with the itinerant electrons, leading to the observed enhancement of the electronic specific heat coefficients.