Upconversion of Nd3+ in Nd3+-Yb3+ Co-Doped Transparent Glass Ceramics Embededing Nano Ca5(Po4)3F Crystals

A transparent glass ceramics co-doped with Nd
³⁺
-Yb
³⁺
was fabricated by the high-temperature melting technique. X-ray diffraction and transmission electron microscope results demonstrated that Ca
₅
(PO
₄
)
₃
F (FAP) nanocrystals with a mean size of 30 nm were homogeneously precipitated among the glass matrix. Upconversion (UC) luminescence of Nd
³⁺
sensitized by Yb
³⁺
was investigated, and emission bands centered at 751, 806 and 875 nm, which corresponds to the
⁴
F
_7/2
→
⁴
I
_9/2
,
⁴
F
_5/2
→
⁴
I
_9/2
and
⁴
F
_3/2
→
⁴
I
_9/2
transitions of Nd
³⁺
, respectively, could be observed. The results show that the order parameter n of UC luminescence intensities depended on excitation pump power increase remarkably after precipitation of nano FAP, which indicating energy distance E = E
_UC
- E(
⁴
F
_3/2
) increase and Nd
³⁺
may incorporate into the precipitated nanocrystals.