Magnetic and Electronic Properties of Li${}_x$CoO${}_2$ Single Crystals

Abstract

Measurements of electrical resistivity ($\rho$), DC magnetization ($M$) and specific heat ($C$) have been performed on layered oxide Li${}_x$CoO${}_2$ (0.25$\le$$x$$\le$0.99) using single crystal specimens. The $\rho$ versus temperature ($T$) curve for $x$=0.90 and 0.99 is found to be insulating but a metallic behavior is observed for 0.25$\le$$x$$\le$0.71. At $T_{\mathrm{S}}$$\sim$155 K, a sharp anomaly is observed in the $\rho$$-$$T$, $M$$-$$T$ and $C$$/$$T$$-$$T$ curves for $x$=0.66 with thermal hysteresis, indicating the first-order charactor of the transition. The transition at $T_{\mathrm{S}}$$\sim$155 K is observed for the wide range of $x$=0.46$-$0.71. It is found that the $M$$-$$T$ curve measured after rapid cool becomes different from that after slow cool below $T_{\mathrm{F}}$, which is $\sim$130 K for $x$=0.46$-$0.71. $T_{\mathrm{F}}$ is found to agree with the temperature at which the motional narrowing in the ${}^7$Li NMR line width is observed, indicating that the Li ions stop diffusing and order at the regular site below $T_{\mathrm{F}}$. The ordering of Li ions below $T_{\mathrm{F}}$$\sim$130 K is likely to be triggered and stabilized by the charge ordering in CoO${}_2$ layers below $T_{\mathrm{S}}$.

8 pages, 7 figures

References in corpus (8)

• Magnetism and structure of LixCoO2 and comparison to NaxCoO2
• Li diffusion in Li${}_x$CoO${}_2$ probed by muon-spin spectroscopy
• Electronic phase diagram of the layered cobalt oxide system, LixCoO2 (0.0 <= x <= 1.0)
• Sodium vacancy ordering and the co-existence of localized spins and itinerant charges in NaxCoO2
• Electronic texture of the thermoelectric oxide Na0.75CoO2
• ^{59}Co NMR evidence for charge ordering below T_{CO}\sim 51 K in Na_{0.5}CoO_2
• Measurement of electron correlations in LixCoO2 (x=0.0 - 0.35) using 59Co nuclear magnetic resonance and nuclear quadrupole resonance techniques
• Crystal-to-stripe reordering of sodium ions in NaxCoO2 (x>=0.75)

Cited by in corpus (7)

• Impact of lithium composition on the thermoelectric properties of the layered cobalt oxide system LixCoO2
• Ultrathin 2D-oxides: a perspective on fabrication, structure, defect, transport, electron and phonon properties
• Prediction of Li intercalation voltages in rechargeable battery cathode materials: effects of exchange-correlation functional, van der Waals interactions, and Hubbard $U$
• Compositional phase stability of correlated electron materials within DFT+DMFT
• Electronic phase diagram of LixCoO2 revisited with potentiostatically de-intercalated single crystals
• Compositional phase stability of strongly correlated electron materials within DFT+$U$
• Novel electronic states realized by the interplay between Li diffusion and Co${}^{3+}$$/$Co${}^{4+}$ charge ordering in Li${}_{\mathrm{x}}$CoO${}_2$