Novel Ba_3Y(PO_4)_3:Sm~(3+),Eu~(3+)(BYP:Sm~(3+),Eu~(3+)) phosphor were synthesized by a standard solid-state reaction under normal ambient air and their structural and optical properties were investigated.X-ray diffraction(XRD) patterns and diffuse reflection spectra(DRS) were used to explore their structural properties.XRD showed that single cubic phase phosphor was obtained.The photoluminescence properties,energy transfer and concentration quenching were investigated in the excitation and emission spectra...