Structural and Optical Properties of Samarium DopedCalcium Fluoride Nanoparticles Synthesized By Co-Precipitation Technique
CaF2
nanoparticles doped with 0, 1, 2, 3, 4 and 5 mol% Sm
3+
were prepared by co-precipitation method. These nanoparticles were studied by X-ray diffraction (XRD), transmission
electron microscopy (TEM), photoluminescence (PL), photoluminescence excitation (PLE)
spectra, energy-dispersive X-ray spectroscopy (EDS)and diffuse reflective spectra. The XRD
patterns indicate cubic structure of CaF
2
and no other impurities. TEM images show that CaF
2
nanoparticles have size varying from 15 to 20 nm. The photoluminescence spectra show 4 peaks at
566 nm, 604 nm, 645 nm and 704 nm, which are assigned to different transitions from the
4
G(4)5/2
excited state to the
6
HJ
with J = 5/2; 7/2; 9/2 and 11/2 ground states of Sm
3+
ions. The PLE spectra
show 8 lines, which are attributed to the absorption transitions from the
6
H5/2ground state to the
4
H(1)9/2,
4
D(2)3/2,
6
P
7/2,
4
F(3)
7/2,
6
P
5/2,
4
M17/2,
4
I(3)13/2 and
4
M15/2 excited states. Six lines among eight
excitation lines were observed in the diffuse reflection spectra