Magnetic field dependence of low temperature specific heat of spinel oxide superconductor LiTi2O4 has been elaborately investigated. In the normal state, the obtained electronic coefficient of specific heat γn = 19.15 mJ/mol K2, the Debye temperature ΘD=657 K and some other parameters are compared with those reported earlier. The superconducting transition at Tc∼11.4 K is very sharp (ΔTc∼0.3 K) and the estimated δC/γnTc is ∼1.78. In the superconducting state, the best fit of data leads to the electronic specific heat C es/γnTc=9.87 exp(-1.58 Tc/T) without field and γ(H) ∝ H0.95 with fields. In addition, Hc2(0)∼11.7 T, Hc(0)∼0.32 T, ξGL(0) ∼55 Å, λGL(0)∼1600 Å, and H c1(0)∼26 mT are estimated from the Werthamer-Helfand-Hohenberg (WHH) theory or other relevant relations. All results from the present study indicate that LiTi2O4 can be well described by a typical type-II, BCS-like, moderate coupling, and fully gapped superconductor in the dirty limit. It is further suggested that LiTi2O4 is a moderately electron-electron correlated system.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 1 Aug 2004|