Novel Phase Transition and the Pressure Effect in YbFe₂Al₁₀-type Ce<i>T</i>₂Al₁₀(<i>T</i>= Fe, Ru, Os)

Abstract

We have succeeded in growing single crystals of orthorhombic CeT2Al10 (T=Fe,\nRu, Os) by Al self-flux method for the first time, and measured the electrical\nresistivity at pressures up to 8 GPa, the magnetic susceptibility and specific\nheat at ambient pressure. These results indicate that CeT2Al10 belongs to the\nheavy fermion compounds. CeRu2Al10 and CeOs2Al10 show a similar phase\ntransition at T0 = 27.3 and 28.7 K, respectively. The temperature dependences\nin the ordered phases are well described by the thermally activated form,\nsuggesting that partial gap opens over the Fermi surfaces below T0. When\npressure is applied to CeRu2Al10, T0 disappears suddenly between 3 and 4 GPa,\nand CeRu2Al10 turns into a Kondo insulator, followed by a metal. The similarity\nof CeT2Al10 under respective pressures suggests a scaling relation by some\nparameter controlling the unusual physics in these compounds.\n