Crystal Structure and Luminescent Properties of a New Rare-earth Borate K_3Pr_3(BO_3)_4

A new borate K_3Pr_3(BO_3)_4 has been prepared using a high temperature flux method and structurally characterized by single-crystal X-ray diffraction analyses.It crystallizes in triclinic system,space group ■ with a=9.0814(10),b=10.8052(12),c=14.0885(16)?,α=69.800(1)°,β=89.922(1)o,γ=89.892(1)°,V=1297.4(3)?~3,Z=4,M_r=775.27,D_c=3.969 g/cm~3,F(000)=1400,μ(Mo Kα)=12.11 mm~(-1),R(F~22σ(F~2))=0.028 and wR(F~2)=0.054.Interestingly,the crystal of K_3Pr_3(BO_3)_4 was twinned by pseudo-merohedry that is mimic monoclinic space group P2/c.The structure of K_3Pr_3(BO_3)_4 exhibits a three-dimensional(3D)network based on isolated anionic(BO_3)~(3-)units that are further bridged by K~+and Pr~(3+)ions.Furthermore,X-ray diffraction(XRD),IRspectrum and photoluminescence(PL)properties were studied.