TY - JOUR
T1 - Heat capacity proportional to T2 induced by Ru substitution in CaCu3 (Ti4-x Rux) O12 (x≈0.5)
AU - Tsukada, I.
AU - Kammuri, R.
AU - Kida, T.
AU - Yoshii, S.
AU - Takeuchi, T.
AU - Hagiwara, M.
AU - Iwakawa, M.
AU - Kobayashi, Wataru
AU - Terasaki, I.
PY - 2009/2/26
Y1 - 2009/2/26
N2 - The effect of Ru substitution for Ti on the ground-state properties of three-dimensional antiferromagnet (AF) CaCu3 Ti4 O12 is studied by means of magnetic susceptibility and heat-capacity measurements. A small amount of Ru substituted for Ti suppresses AF long-range order and induces a new intermediate state with T2 -proportional heat capacity, which shows a clear contrast to a simple spin-dilution effect demonstrated by the Zn substitution for Cu. Ru substitution also creates a finite density of state at the Fermi level while keeping nominal valence of Cu ions to be 2+, which is essential to a novel insulator-to-metal crossover driven by an isovalent substitution of Ru4+ for Ti4+.
AB - The effect of Ru substitution for Ti on the ground-state properties of three-dimensional antiferromagnet (AF) CaCu3 Ti4 O12 is studied by means of magnetic susceptibility and heat-capacity measurements. A small amount of Ru substituted for Ti suppresses AF long-range order and induces a new intermediate state with T2 -proportional heat capacity, which shows a clear contrast to a simple spin-dilution effect demonstrated by the Zn substitution for Cu. Ru substitution also creates a finite density of state at the Fermi level while keeping nominal valence of Cu ions to be 2+, which is essential to a novel insulator-to-metal crossover driven by an isovalent substitution of Ru4+ for Ti4+.
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U2 - 10.1103/PhysRevB.79.054430
DO - 10.1103/PhysRevB.79.054430
M3 - Article
AN - SCOPUS:62549147601
SN - 1098-0121
VL - 79
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 5
M1 - 054430
ER -