Fabrication of glass-ceramics containing spin-chain compound SrCuO₂ and its high thermal conductivity

High thermal conductivity materials are in great demand for heat-flow control and heat dissipation in electronic devices. In this study, we have produced a glass-ceramics that contains spin-chain compound SrCuO₂ and have found that the glass-ceramics yields high thermal conductivity of ∼5 W K^-1 m^-1 even at room temperature. The glass-ceramics is fabricated through crystallization of inhomogeneous melt-quenched oxides made from SrCO₃, CuO, Li₂CO₃, Ga₂O₃, and Al₂O₃. Transmission electron microscopy and X-ray and electron diffraction reveal that SrCuO₂ crystallites with a size of 100-200 nm are precipitated in the glass-ceramics. The highness of the thermal conductivity is attributable to two sources: one is elongation of phonon mean free path due to the crystallization of the inhomogeneous structure or structural ordering. The other is emergence of the heat carriers, spinons, in the SrCuO₂. This highly thermal conductive glass-ceramics is expected to be utilized as base materials for heat-flow control devices.