How similar are amorphous calcium carbonate and calcium phosphate? A comparative study of amorphous phase formation conditions

AbstractWe report a synthesis strategy for pure hydroxyapatite (HAp) using an amorphous calcium carbonate (ACC) colloid as the starting source. Room-temperature phosphorylation and subsequent calcination produce pure HAp via intermediate amorphous calcium phosphate (ACP). The pre-calcined sample undergoes a competitive transformation from ACC to ACP and crystalline calcium carbonate. The water content, ACC concentration, Ca/P molar ratio, and pH during the phosphorylation reaction play crucial roles in the final phase of the crystalline phosphate compound. Pure HAp is formed after ACP is transformed from ACC at a low concentration (1 wt%) of ACC colloid (1.71 < Ca/P < 1.88), whereas Ca/P = 1.51 leads to pure β-tricalcium phosphate. The ACP phases are precursors for calcium phosphate compounds and may determine the final crystalline phase.

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Amorphous phase formation in Ti/Ni bilayer thin films by solid-state diffusion

Journal of Materials Science Letters ◽

10.1007/bf00720198 ◽

1989 ◽

Vol 8 (12) ◽

pp. 1393-1394 ◽

Cited By ~ 13

Author(s):

Masahiro Kitada ◽

Noboru Shimizu ◽

Teruho Shimotsu

Keyword(s):

Thin Films ◽

Solid State ◽

Amorphous Phase ◽

Phase Formation ◽

Solid State Diffusion ◽

State Diffusion ◽

Amorphous Phase Formation

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Amorphous phase formation in irradiated intermetallic compounds

Radiation Effects ◽

10.1080/00337578308228192 ◽

1983 ◽

Vol 77 (3-4) ◽

pp. 273-293 ◽

Cited By ~ 122

Author(s):

J. L. Brimhall ◽

H. E. Kissinger ◽

L. A. Charlot

Keyword(s):

Intermetallic Compounds ◽

Amorphous Phase ◽

Phase Formation ◽

Amorphous Phase Formation

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Amorphous phase formation in ion implanted cobalt

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/s0168-583x(87)80113-1 ◽

1987 ◽

Vol 19-20 ◽

pp. 566-570 ◽

Cited By ~ 1

Author(s):

Wen-Zhi Li ◽

Zaki Al-Tamimi ◽

W.A. Grant

Keyword(s):

Amorphous Phase ◽

Phase Formation ◽

Amorphous Phase Formation ◽

Ion Implanted

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Amorphous Phase Formation During Ion Mixing of Ti/Si Bilayers at Elevated Temperature

MRS Proceedings ◽

10.1557/proc-100-63 ◽

1988 ◽

Vol 100 ◽

Cited By ~ 1

Author(s):

K. Maex ◽

R. F. De Keersmaecker ◽

M. Van rossum ◽

W. F. Van Der Weg

Keyword(s):

Elevated Temperature ◽

Thermal Treatment ◽

Diffusion Couple ◽

Amorphous Phase ◽

Phase Formation ◽

Multilayer Structure ◽

Elevated Temperatures ◽

Binary Diffusion ◽

Amorphous Phase Formation

ABSTRACTThe amorphous phaseformation in Ti-Si bilayers upon ion mixing at elevated temperatures and in Ti-Si multilayers upon thermal treatment was studied. In the case of ion mixing with 5×1015 cm−2 Xe atoms at temperatures around 240°C a 100nm thick amorphous Ti-Si alloy is formed with a very homogeneous Ti:Si=3 :4 composition. Thermal treatment of the Ti-Si multilayer structure at similar temperatures also yields amorphous silicide layers. The results are interpreted according to the evolution in a planar binary diffusion couple, where the Si and Ti concentrations in the reacted layer are dictated by thermodynamic and kinetic arguments.

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