Phosphor
Provided is a phosphor, which is excited by a wide band of visible light, capable of emitting near-infrared light of high intensity. The phosphor comprises a crystal phase represented by a formula (1): MCuSi 2 O 6 (where M comprises one or more of Ba, Sr and Ca), and a crystal phase represented by a formula (2): MCuSi 4 O 10 (where M comprises one or more of Ba, Sr and Ca), wherein a ratio β of a diffraction peak intensity of MCuSi 4 O 10 with respect to a diffraction peak intensity of MCuSi 2 O 6 in an X-ray diffraction (XRD) pattern obtained by powder XRD measurement using CuKα rays is 0<β≤0.50.
1. A phosphor, comprising
a crystal phase represented by a formula (1): MCuSi 2 O 6 (where M comprises one or two or more of Ba, Sr and Ca) and
a crystal phase represented by a formula (2): MCuSi 4 O 10 (where M comprises one or two or more of Ba, Sr and Ca),
wherein, in an X-ray diffraction (XRD) pattern obtained by powder XRD measurement using CuKα rays, a ratio β of a diffraction peak intensity of MCuSi 4 O 10 with respect to a diffraction peak intensity of MCuSi 2 O 6 is 0<β≤0.50,
wherein the phosphor further comprises a SiO 2 crystal phase, and
wherein, in an X-ray diffraction (XRD) pattern obtained by powder XRD measurement using CuKα rays, a ratio α of a diffraction peak intensity of SiO 2 with respect to a diffraction peak intensity of MCuSi 2 O 6 is 0<α<0.45.
2. The phosphor according to claim 1 , comprising a compound in which a part of Cu in the formula (1): MCuSi 2 O 6 or the formula (2): MCuSi 4 O 10 , or both the formulae is substituted by Mg or Zn, or both of these.
3. The phosphor according to claim 2 , further comprising one or two or more elements selected from a group consisting of Li, Na, K, B, P, F, Cl, Br and I at 0.005 to 3% by mass.
4. The phosphor according to claim 1 , further comprising one or two or more elements selected from a group consisting of Li, Na, K, B, P, F, Cl, Br and I at 0.005 to 3% by mass.
5. A near-infrared luminescent device comprising the phosphor according to claim 1 .
6. A unit comprising the near-infrared luminescent device according to claim 5 , wherein the unit is a near-infrared spectrometer or an optical coherence tomography unit.
7. A fluorescent paint comprising the phosphor according to claim 1 .
8. A substrate printed with the fluorescent paint according to claim 7 .
9. A near-infrared luminescent device comprising a phosphor, wherein the phosphor comprises a crystal phase represented by a formula (1): MCuSi 2 O 6 (where M comprises one or two or more of Ba, Sr and Ca) and
a crystal phase represented by a formula (2): MCuSi 4 O 10 (where M comprises one or two or more of Ba, Sr and Ca), and
wherein, in an X-ray diffraction (XRD) pattern obtained by powder XRD measurement using CuKα rays, a ratio β of a diffraction peak intensity of MCuSi 4 O 10 with respect to a diffraction peak intensity of MCuSi 2 O 6 is 0<β≤0.50.
10. A unit comprising the near-infrared luminescent device according to claim 9 , wherein the unit is a near-infrared spectrometer or an optical coherence tomography unit.
11. A fluorescent paint comprising a phosphor, wherein the phosphor comprises a crystal phase represented by a formula (1): MCuSi 2 O 6 (where M comprises one or two or more of Ba, Sr and Ca) and
a crystal phase represented by a formula (2): MCuSi 4 O 10 (where M comprises one or two or more of Ba, Sr and Ca), and
wherein, in an X-ray diffraction (XRD) pattern obtained by powder XRD measurement using CuKα rays, a ratio β of a diffraction peak intensity of MCuSi 4 O 10 with respect to a diffraction peak intensity of MCuSi 2 O 6 is 0<β≤0.50.
12. A substrate printed with the fluorescent paint according to claim 11 .