Abstract: Hydroxyapatite (HA) is an excellent bone substitute materials.Magnesium doped HA (Mg-HA) whiskers can not noly enhance the biological properties of HA, also be used as reinforcement for biomedical materials.However, incorporation of Mg2+ into HA would change the crystal structure and affect their thermal stability.Thus, Mg-HA whiskers were prepared by a hydrothermal synthesis method, and their crystal structure, thermal stability and the influencing factors of the Mg-HA whiskers were studied by XRD, FTIR and SEM.The results show that the crystallinity of HA decrease with the increase of magnesium ion doping content when the magnesium ion doping content is less than 5;, and the cell parameters a is basically unchanged, and c is gradually reduced.When magnesium ion doping increase to 8;, a small amount of impurity peaks assign as Ca7Mg2P6O24 appear.Mg-HA would decompose at 800 ℃, forming HA/β-TCP bipasic calcium phosphate.Magnesium ion doping content, calcination temperature and bioglass addition are found significantly to enhance the decomposition of HA.

Key words: Hydroxyapatite (HA) is an excellent bone substitute materials.Magnesium doped HA (Mg-HA) whiskers can not noly enhance the biological properties of HA, also be used as reinforcement for biomedical materials.However, incorporation of Mg2+ into HA would change the crystal structure and affect their thermal stability.Thus, Mg-HA whiskers were prepared by a hydrothermal synthesis method, and their crystal structure, thermal stability and the influencing factors of the Mg-HA whiskers were studied by XRD, FTIR and SEM.The results show that the crystallinity of HA decrease with the increase of magnesium ion doping content when the magnesium ion doping content is less than 5;, and the cell parameters a is basically unchanged, and c is gradually reduced.When magnesium ion doping increase to 8;, a small amount of impurity peaks assign as Ca7Mg2P6O24 appear.Mg-HA would decompose at 800 ℃, forming HA/β-TCP bipasic calcium phosphate.Magnesium ion doping content, calcination temperature and bioglass addition are found significantly to enhance the decomposition of HA.