Ionic conduction in apatite solid solutions

Yamashita, Kimihiro; Owada, Hitoshi; Umegaki, Takao; Kanazawa, Takafumi; Futagami, T.

doi:10.1016/s0167-2738(88)80121-8

Cited by 68 publications

(49 citation statements)

References 6 publications

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“…It is worthwhile to notice that a high ionic conductivity appears to enhance the electrical induced osteoconductivity and osseointegration of HA implants [43 45], which is favored by the presence of anion va cancies in the HA lattice [31,46,47]. Then, it is expected that the addition of Y 2 O 3 to HA improves osteoblast adhesion and bone bonding to the HA implants besides increasing its thermal stability and improving other properties related with the processing conditions such as the elastic constants, mechanical strength and microhardness.…”

Section: Xrd and Ftir Measurementsmentioning

confidence: 99%

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

Parente

Savoini

Ferrari

et al. 2013

Materials Science and Engineering: C

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Abstract:The capability of the colloidal method to produce yttria (Y 2 O 3 ) dispersed hydroxyapatite (HA) has been in vestigated as an alternative method to the conventional method of mechanical mixing and sintering for de veloping HA based materials that could exhibit controllable and enhanced functional properties. A water based colloidal route to produce HA materials with highly dispersed Y 2 O 3 has been applied, and the effect of 10 wt.% Y 2 O 3 addition to HA investigated by thermal analysis, X ray diffraction and Fourier transform in frared spectroscopy. These measurements evidence a remarkable effect of this Y 2 O 3 addition on decomposi tion mechanisms of synthetic HA. Results show that incorporation of Y 2 O 3 as dispersed second phase is beneficial because it hinders the decomposition mechanisms of HA into calcium phosphates. This retardation will allow the control of the sintering conditions for developing HA implants with improved properties. Be sides, substitution of Ca 2+ with Y 3+ ions appears to promote the formation of OH − vacancies, which could improve the conductive properties of HA favorable to osseointegration.

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Section: Xrd and Ftir Measurementsmentioning

confidence: 99%

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

Parente

Savoini

Ferrari

et al. 2013

Materials Science and Engineering: C

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“…For example, a surface ionic conductivity of both porous and dense HA bioceramics was examined for humidity sensor applications, since the room temperature conductivity was influenced by relative humidity [326]. Namely, the ionic conductivity of HA has been a subject of research for its possible use as an alcohol [327], carbon dioxide [327] or carbon monoxide [328] gas sensors. Electrical measurements have also been used as a characterization tool to study the evolution of microstructure in HA bioceramics [329].…”

Section: Electrical Propertiesmentioning

confidence: 99%

Medical Application of Calcium Orthophosphate Bioceramics

Dorozhkin¹

2011

BIO

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In the late 1960's, a strong interest was raised in biomedical applications of ceramic materials (named bioceramics a little bit later). Bioceramics was initially used as reasonable alternatives to metals in order to increase their biocompatibility. However, within a short period, it has grown into a diverse class of biomaterials, presently including three essential types: relatively bioinert, bioactive (or surface reactive) and bioresorbable bioceramics. This review is limited to bioceramics prepared from calcium orthophosphates only, which belong to the categories of bioactive and bioresorbable compounds. There have been a number of important advances in this field during the past 30 -40 years. The research was shifted from an initial study on the develop-ment of bioinert bioceramics towards bioactive and bioresorbable bioceramics, and these different types of calcium orthophosphate bioceramics can be tuned through the structural and compositional control. At the turn of the millennium, a new concept of calcium orthophosphate bioceramics has been developed to promote a regeneration of bones. Current biomedical applications of calcium orthophosphate bioceramics include artificial replacements for hips, knees, teeth, tendons and ligaments, as well as repair for periodontal disease, maxillofacial reconstruction, augmenttation and stabilization of the jawbone, spinal fusion and bone fillers after tumor surgery. Potential future applications of calcium orthophosphate bioceramics are demonstrated in drug delivery systems, effective carriers of growth factors, bioactive peptides and/or various types of cells for tissue engineering purposes.

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“…The conductivity of a conductive site is independent of frequency, since σ = 1/R, while the a. c. conductivity of a capacitive site rises linearly with frequency, since σ = 2πfC. The conduction mechanism in Pure-HAP is either due to a proton hopping along the c-axis between electroactive O 2-anion or to an OH -ion interacting with the double bonded oxygen of a PO 4 groups [62][63][64]. On the other hand, OH -in the lattice of hydroxyapatite is thought to contribute to the ionic concduction at elevated temperature, although the conductivity is relatively low in comparision with other typical ionic conductor [65].…”

Section: +2mentioning

confidence: 99%

FTIR, powder XRD, TEM and dielectric studies of pure and zinc doped nano‐hydroxyapatite

Tank

Sharma

Kanchan

et al. 2011

Cryst. Res. Technol.

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Hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 or HAP, is an important bio-material, which is having application in bone implants and dentistry. In the present study, zinc doped nano-hydroxyapatite (Zn-HAP) was synthesized via chemical precipitation route using surfactant mediated approach. The doping of zinc was confirmed by EDAX. The powder X-ray diffraction (XRD) pattern revealed the typical hydroxyapatite pattern with broadening and extra peaks were observed for higher concentration. The average crystallite size was calculated by applying the Scherrer's formula to powder XRD pattern and was found in the range of 16 to 33 nm. The morphology of synthesized nano-particles was also confirmed using TEM. FTIR spectroscopy was used to confirm the presence of various bonds. The dielectric study was carried out at room temperature within the frequency range from 10 2 Hz to 10 7 Hz and the variations of dielectric constant with frequency of applied field as well as with the concentration of zinc were studied. It was found that as the concentration of zinc increased the dielectric constant increased. The variations of dielectric loss and a.c. conductivity with frequency of applied field were studied.

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Ionic conduction in apatite solid solutions

Cited by 68 publications

References 6 publications

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

Medical Application of Calcium Orthophosphate Bioceramics

FTIR, powder XRD, TEM and dielectric studies of pure and zinc doped nano‐hydroxyapatite

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