posted on 2021-09-16, 13:08authored byQi Wu, Can Yang, Jie Ma, Fei Liang, Chunlin Teng, Yeshuang Du
A new
alkali metal–rare earth metal anhydrous sulfate, KTb(SO4)2 (KTSO), was synthesized by a hydrothermal method.
It crystallized in the non-centrosymmetric (NCS) orthorhombic space
group P212121 with
cell parameters a = 5.43950(10), b = 8.8579(3), c = 13.3962(4), Z = 2. Its structure is composed of [KO11], [TbO8], and [SO4] groups, which are interconnected to constitute
a one-dimensional (1D) chain, and then further linked to construct
a three-dimensional (3D) network structure through [SO4] units. The results of the powder frequency doubling test show that
KTb(SO4)2 has a phase-matching second-order
nonlinear optical effect of 0.3 times that of KH2PO4 (KDP). The measured birefringence of the crystal (0.01) agrees
well with the calculated value (0.019). Meanwhile, its infrared and
ultraviolet spectrum and thermal properties were studied, respectively.
Its optical properties and band gap structure are studied by theoretical
calculation. This work provides a NCS structure of anhydrous sulfates
and offers guidance for further exploration of new anhydrous sulfates.