Evolution Of The Electronic Specific Heat Of (la1-xcex)3al

The specific heat of (La1-xCex)3Al was measured in the temperature range from 2 to 30 K as function of the Ce concentration. The electronic specific heat for small x is close to the normal metal value (14 mJ/K2 mol f.u.), increasing to a maximum of 410 mJ/K2 mol Ce for x∼0.4. characterizing a heavy-fermion behavior around this concentration. Above this critical concentration, the electronic specific heat decreases to 140 mJ/K2 mol Ce for x= 1. From the fitting of the experimental data to Debye and Schottky type Kondo and crystal field contributions we estimated the Kondo temperature. θD, Δ1, and Δ2. Tk was found to increase with Ce concentration. Our results are interpreted in view of the competition between Kondo effect and Ruderman-Kittel-Kasuya-Yosida interaction, © 1997 American Institute of Physics.818 PART 2A41794181Blanco, J.A., De Podesta, M., Espeso, J.I., GomezSal, J.C., Lester, C., McEwen, K.A., Patrikios, N., Fernandez, J.R., (1994) Phys. Rev. B, 49, p. 15126Suzuki, T., Aoki, Y., Nishigori, S., Fujita, T., Murashita, Y., Sakurai, J., (1990) J. Magn. Magn. Mater., 90-91, p. 482Sakurai, J., Murashita, Y., Aoki, Y., Fujita, T., Takabatake, T., Fujii, H., (1989) J. Phys. Soc. Jpn., 58, p. 4078Chen, Y.Y., Lawrence, J.M., Thompson, J.D., Willis, J.O., (1989) Phys. Rev. B, 40, p. 10766Buschow, K.H.J., (1965) Philips Res. Rep., 20, p. 337Evans, S.M.M., Bhattacharjee, A.K., Coqblin, B., (1991) Physica B, 171, p. 293Brandt, N.B., Muschkovich, V.V., (1984) Adv. Phys., 33, p. 373Rajan, V.T., (1983) Phys. Rev. Lett., 51, p. 308Sereni, J.G., (1995) Physica B, 215, p. 273Bredl, C.D., Steglich, F., Schotte, K.D., (1978) Z. Phys. B, 29, p. 32