SPIN FLUCTUATION AND MAGNETIC PHASE-TRANSITION IN ITINERANT HEAVY-ELECTRON SYSTEM CE(RU1-XRHX)(2)SI-2 (X = 0, 0.03 AND 0.05)

The specific heats and the susceptibilities of Ce(Ru1-xRhx)(2)Si-2 sin gle crystals (x = 0, 0.03 and 0.05) were studied between 0.1 and 10 K. The magnetic ground state of Ce(Ru1-xRhx)(2)Si-2 is found to be a Fer mi liquid even near the critical concentration x = 0.03. x = 0.05 comp ound takes place a spin density wave transition at around 2 K, which i s an antiferromagnetic order of itinerant heavy electrons by nesting i n the Fermi liquid state. The low temperature behavior of the specific heat and the susceptibility were well explained by the effect of spin fluctuations based on the SCR theory.