Publication Date:
2016-11-03
Description:
We observed a critical phenomenon of ferroelectric transition in hydroxyapatite (HAp) through measuring the thermally stimulated depolarization current of polycrystalline monoclinic HAp. Two peaks attributable to hydroxide (OH − ) ion dipole reorientations were observed. The one was very sharp, the other displayed a broad peak ranging from 350 K to 550 K. While the broad peak can be attributed to the diffusive reorientation motions of OH − ion dipoles, the sharp peak, related to the ferroelectric phase transition, implies the presence of ferroelectricity in HAp. The sharp peak was found near 380 K, the phase-transition temperature from the monoclinic to hexagonal is ascribed to a critical phenomenon caused by the ferroelectric behavior of OH − ion dipole reorientations.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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