Inhomogeneity of composition in near-stoichiometric LiNbO3 single crystal grown from Li rich melt

Abstract

A near-stoichiometric LiNbO 3 single crystal has been grown by the Czochralski technique from a melt of 58.5 mol% Li 2 O. Its composition homogeneity was assessed by measuring the UV absorption edge. It was found that the maximum composition difference is about 0.03 mol% in the radial direction and 0.05 mol% in the axial direction. Differential scanning calorimetry (DSC) analysis was performed on the powder from the synthesized raw material and the frozen melt after crystal growth. The analytical results indicate that, during crystal growth, the magnitude of lithium volatilization from the melt surface is more than the degree of segregation from the crystal. . The volatilized lithium diffuses s into the crystal to compensate for the lithium segregation in the LiNbO 3 crystal.

Growth of MgO doped near stoichiometric LiNbO3 single crystals by a hanging crucible Czochralski method using a ship lockage type powder feeding system assisted by numerical simulation

“…The variance in the Li content is affected by multiple factors, such as lithium segregation, volatilization of lithium from the melt surface, and other growth parameters. 26 The results of the proposed growth method demonstrate the good compositional uniformity along both the radial and axial directions. Compared to the results for the SLN sample, the absorption edge of MgOSLN (1 mol%) is blue shifted to ~304.3 nm, and is almost the same for head and tail.…”

“…The calculated Li contents are identical to the values determined using the Curie temperature. The variance in the Li content is affected by multiple factors, such as lithium segregation, volatilization of lithium from the melt surface, and other growth parameters 26. The results of the proposed growth method demonstrate the good compositional uniformity along both the radial and axial directions.…”

“…In previous reports, SLN and MgOSLN crystals were grown using the conventional CZ method. [26][27][28] A hanging double crucible system comprising a Pt crucible, as well as a Pt ring with connecting Pt wires on the edge of the crucible, was adopted for growing SLN crystals. 29 This modified hanging crucible Czochralski (HCCZ) method could be used to improve the quality and produce large amounts of these crystals by substituting the inner crucible used in the DCCZ method with a hanging Pt sleeve, and this method has been successfully used in the growth of single SLN crystals in this study.…”