TY - JOUR
T1 - Isotope effect in Lix ZrNCl superconductors
AU - Taguchi, Y.
AU - Kawabata, T.
AU - Takano, T.
AU - Kitora, A.
AU - Kato, K.
AU - Takata, M.
AU - Iwasa, Y.
PY - 2007/8/8
Y1 - 2007/8/8
N2 - The N-isotope effect has been investigated for a series of layered superconductors Lix ZrNCl with small carrier density. The N-vibration phonon mode around 615 cm-1 interacting most strongly with electronic system has shown softening by about 20 cm-1 (=3.3%) upon N15 substitution. On the other hand, the decrease in the superconducting critical temperature (Tc) upon N15 substitution has been found to be only 0.06±0.03 K (=0.5±0.3%). This small change in Tc corresponds to an isotope shift coefficient α=0.07±0. 04, which is much smaller than the conventional value of 0.5, implying the relevance of other fluctuations than the phonon to the pairing interaction.
AB - The N-isotope effect has been investigated for a series of layered superconductors Lix ZrNCl with small carrier density. The N-vibration phonon mode around 615 cm-1 interacting most strongly with electronic system has shown softening by about 20 cm-1 (=3.3%) upon N15 substitution. On the other hand, the decrease in the superconducting critical temperature (Tc) upon N15 substitution has been found to be only 0.06±0.03 K (=0.5±0.3%). This small change in Tc corresponds to an isotope shift coefficient α=0.07±0. 04, which is much smaller than the conventional value of 0.5, implying the relevance of other fluctuations than the phonon to the pairing interaction.
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U2 - 10.1103/PhysRevB.76.064508
DO - 10.1103/PhysRevB.76.064508
M3 - Article
AN - SCOPUS:34547850395
SN - 1098-0121
VL - 76
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 6
M1 - 064508
ER -