Method for fabricating apatite crystals and ceramics

A crystalline form of a compound of formula Ib:

• (Ca1−nYbn)5(PO4)3F (Ib)
• wherein subscript n is about 0.01, and
• wherein the X-ray crystal structure of the compound has the following 2-theta peaks:
• 25.978, 31.780, 32.319, 32.779, 34.082 and 49.520,
• the compound prepared by the process comprising:
• dissolving Ca5(PO4)3F in an aqueous solution comprising concentrated hydrochloric acid and ytterbium, wherein the solution is at a temperature of from about 0 to about 100° C.;
• and
• adding concentrated ammonium hydroxide to the solution to neutralize the solution, thereby preparing the crystalline form of (Ca1−n Ybn)5(PO4)3F, where subscript n is about 0.01, thereby preparing the crystalline form of the compound of formula Ib.

A method of preparing a crystalline form of a compound of formula I:

• (A1−nYn)5(PO4)3X (I)
• wherein
• A is selected from the group consisting of Ca, Sr and Ba,
• Y is a dopant selected from the group consisting of Yb, Nd, Ce, Cr, Tm, Ho, Er, and Sm,
• subscript n is from about 0.001 to about 0.1, and
• X is selected from the group consisting of F, Cl and OH,
• the method comprising:
• dissolving an alkaline earth fluoride, an alkaline earth phosphate, an alkaline earth carbonate and a salt of the dopant Y in an aqueous solution comprising an acid, wherein the solution is at a temperature of from about 0 to about 100° C.;
• and
• forming a supersaturated solution of the compound of formula I, thereby preparing a crystalline form of the compound of formula I.