LAUSR

Abstract We report on the crystal growth, structure determination and the vibronic and spectroscopic properties of a novel red-emitting anisotropic crystal featured by a layered structure, the Eu 3+ -doped orthorhombic potassium yttrium double molybdate crystal, KY(MoO 4 ) 2 . The transition probabilities of Eu 3+ ions are determined within the Judd-Ofelt theory. The stimulated-emission cross-sections are calculated for the 5 D 0 → 7 F J transitions of Eu 3+ with polarized light. The maximum σ SE reaches 11.4 × 10 −20  cm 2  at 613.9 nm for E || c . The strong anisotropy of the spectroscopic properties of Eu 3+ is attributed to the layered structure of KY(MoO 4 ) 2 . The lifetime of the 5 D 0 state is 0.65 ms. Under UV excitation, Eu:KY(MoO 4 ) 2 provides red emission ( CIE 1931 coordinates, x  = 0.665 and y  = 0.335) with almost unity color purity. Eu 3+ ions are studied as structural probes, revealing a single type of site (C 2 symmetry). The polarization-anisotropy of the purely magnetic-dipole 5 D 0 → 7 F 1 transition is discussed. Eu:KY(MoO 4 ) 2 is promising for red phosphors and deep-red lasers.