Pressure Studies On The Antiferromagnetic Kondo Semiconductor Ce(Ru1-Xrhx)(2)Al-10 (X=0,0.1)

We examined the electrical resistivity (rho) of antiferromagnetic (AFM) Kondo semiconductors Ce(Ru1-xRhx)(2)Al-10 (x = 0 and 0.1) under pressure in order to obtain information on the electronic states under pressure, especially near the critical pressure (P-c) from the AFM ordered state to the paramagnetic one, where the Ce-4f electron character is a more localized state in x = 0.1 than in x = 0. From the results, nearly the same P-c was obtained; P-c similar to 4.7 and 4.5 GPa in x = 0 and 0.1, respectively. In both samples, the Kondo semiconducting increase of. is observed up to P similar to 3 GPa, above which, however, the increase disappears and a broad maximum appears at high temperatures. Below the maximum,. exhibits a metallic decrease with decreasing temperature down to the AFM transition temperature T-0, suggesting that the c-f hybridization gap could be not necessary to form the unusual AFM order. We also examined pressure effects on the magnetic susceptibility. of both samples up to P similar to 2 GPa, and found that. along the easy axis is strongly suppressed by pressure in both samples. In x = 0, the broad maximum just above T-0 shifts to high temperatures with increasing pressure. On the other hand, for x = 0.1, a clear cusp at T-0 remains sharp and no broad peak appears at least up to 2 GPa. Such a difference in the pressure response of. could originate from the difference in the electronic state between x = 0 and 0.1.