Synthesis and structure-property relations in Nd2xCd2-3xSiO4(0.01 ≤ x ≤0.21) system

Synthesis of Nd2xCd2-3xSiO4 (0.01≤ x ≤ 0.21) (S1-S5: x=0.01, 0.06, 0.11, 0.16, 0.21) system was done by sol-gel method. Powder x-ray diffraction (XRD) patterns of S1-S5 show orthorhombic unit cell and space group Pmna. Infrared spectroscopy (IR) results at 300 K show the presence of tetrahedral [SiO4/2]2- and [CdO4/2]2- units. Optical absorption at ∼ 750 nm is due to 4I9/2→ 4F7/2+ 4S3/2 at ∼ 794-806 nm is due to 4I9/2→ 4F5/2 transition of Nd3+ ion. Energy dispersive analysis of x-rays (EDAX) result of A5 shows the presence Si, Cd in the sample. Electron paramagnetic resonance (EPR) of S1 at 10 K shows axially symmetric lineshape with 8-parallel lines of 143 or 145Nd (I=7/2) and unresolved perpendicular lines with g-parallel lines=2.647, g perpendicular 2.102, A parallel lines= 60 G and A perpendicular = 25 G. While S3 and S5 show isotropic feature with same giso as 2.046. At 77 and 300 K broad lineshapes are observed due to rapid spin lattice relaxation of Nd3+. (author)