Method of producing apatite crystal, and apatite crystal

• US 10,851,472 B2
• Filed: 06/14/2017
• Issued: 12/01/2020
• Est. Priority Date: 06/15/2016
• Status: Active Grant

• Current Assignee: Kochi University, Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Shinomiya, Yu, Yanagisawa, Kazumichi, Sakaki, Masoud
• Primary Examiner(s): Nguyen, Ngoc-Yen
• Application Number:
  US15/622,106
• Publication Number:
  US 20170362737A1
• Time in Patent Office: 1,266 Days
• CPC Class Codes: C01B 25/455 containing halogen completely halogenated alkali metal phosphates C01D, e.g. lithium hexafluorophosphate C01D15/005
• CPC Class Codes: C30B 15/00 Single-crystal growth by pulling from a melt, e.g. Czochralski method under a protective fluid C30B27/00
• CPC Class Codes: C30B 15/36 characterised by the seed, e.g. its crystallographic orientation
• CPC Class Codes: C30B 29/12 Halides
• CPC Class Codes: C30B 29/14 Phosphates
• CPC Class Codes: C30B 29/60 characterised by shape
• CPC Class Codes: C30B 5/00 Single-crystal growth from gels under a protective fluid C30B27/00
• CPC Class Codes: C30B 7/14 the crystallising materials being formed by chemical reactions in the solution
• CPC Class Codes: C30B 9/06 using as solvent a component of the crystal composition
• CPC Class Codes: C30B 9/12 Salt solvents, e.g. flux growth

Abstract

A method of producing an apatite crystal includes the steps of preparing an apatite single crystal expressed by the general formula M²₅(PO₄)₃X (M² being at least atomic element selected from the group consisting of divalent alkaline-earth metals and Eu, and X is at least one atomic selected from the group consisting of halogens); placing the apatite single crystal into a space controllable to a predetermined atmosphere; supplying water vapor into the space; and heating such that the atmosphere in the space is within a 1000° C. to 1400° C. range.

Claims

1. A method of producing an apatite crystal, the method comprising:

preparing a tubular apatite single crystal expressed by the general formula M²₅(PO₄)₃X, wherein M² is at least one atomic element selected from the group consisting of divalent alkaline-earth metals and Eu, and X is at least one atomic element selected from the group consisting of halogens;

placing the apatite single crystal into a space controllable to a predetermined atmosphere;

supplying water vapor into the space; and

heating such that the atmosphere in the space is at a temperature at which a portion of the halogen atoms contained in the apatite single crystal are replaced with hydroxyl groups,

wherein the step of heating is carried out within a 6 to 24 hour range, and

wherein in the step of heating, the heating is such that the atmosphere in the space is in the range of 1100°

C. to 1200°

C.

2. The method according to claim 1, wherein the step of heating is carried out under normal pressure.