Two potential self-activated orthoborates Cd4NdO(BO3)3 and Ca3Nd3(BO3)5: growth, crystal structures and optical properties†
Abstract
Two neodymium orthoborate crystals of Cd4NdO(BO3)3 and Ca3Nd3(BO3)5 were successfully grown using the flux method. Single crystal X-ray diffraction exhibits that Cd4NdO(BO3)3 crystallizes in the monoclinic space group of Cm with unit cell parameters a = 8.0536(14) Å, b = 15.872(2) Å, c = 3.5364(6) Å, β = 100.268(7)° and Ca3Nd3(BO3)5 has a hexagonal space group of P63mc with cell parameters a = 10.4864(2) Å, c = 6.2665(1) Å. Both compounds have high Nd3+ concentration with 4.5 × 1021 ions per cm3 in Cd4NdO(BO3)3 and 1.0 × 1022 ions per cm3 in Ca3Nd3(BO3)5, respectively. The absorption and emission spectra as well as decay curves for the 4F3/2 to 4I11/2 transition of Nd3+ ions in the two compounds were measured at room temperature. The spectra indicate that both two crystals are potential materials as self-activated microchip laser media due to high Nd3+ contents.