Local Structures Around Y Atoms in Y&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-Stabilized Tetragonal ZrO&lt;sub&gt;2&lt;/sub&gt;

Morikawa, Hideki; Shimizugawa, Y.; Μarumo, F.; Harasawa, Takeshi; Ikawa, Hiroyuki; Tohji, Kazuyuki; Udagawa, Yasuo

doi:10.2109/jcersj.96.253

Cited by 37 publications

(16 citation statements)

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“…The calculations explain contradictory experimental reports of whether oxygen vacancies prefer to bind to dopant or host Zr atoms [191][192][193][194][195][196][197][198][199][200][201], and show variations due to the chemical identity of the dopant. The observed ordering tendencies can be well understood in terms of a balance between competing electrostatic and elastic defect interactions, the latter depending on the dopant identity.…”

Section: Defectsmentioning

confidence: 73%

“…Even for the most studied case, yttriastabilized zirconia (YSZ), the experimental results support different defect configurations: while some of them suggest that oxygen vacancies are bonded to the dopant Y [190][191][192][193][194][195][196], others claim host Zr-vacancy bonds [197][198][199][200][201]. The strength of the vacancy-ion bonds is also a matter of discussion.…”

Section: Defectsmentioning

confidence: 99%

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Adhesion at metal–ZrO2 interfaces

Muñoz

Gallego

Beltrán

et al. 2006

Surface Science Reports

183

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Section: Defectsmentioning

confidence: 73%

Section: Defectsmentioning

confidence: 99%

Adhesion at metal–ZrO2 interfaces

Muñoz

Gallego

Beltrán

et al. 2006

Surface Science Reports

183

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“…As a matter of fact, if oxygen “feels” more affinity to fill up the sub-stoichiometric lattice of zirconia, it will not participate or just participate with a reduced activity to the oxidation processes taking place on the polyethylene side of the joint. However, the annihilation of vacancy concentration at the surface of 3Y-TZP unavoidably leads to polymorphic transformation from the tetragonal to the monoclinic phase [64,65,66,67,68]. If transformation progresses toward the sub-surface of the zirconia femoral head, the local volume expansion and surface roughening involved with it might negatively affect the joint lifetime for a different reason: the formation of polyethylene debris due to enhanced abrasive wear.…”

Section: Background On Physical Chemistry Of Bioceramicsmentioning

confidence: 99%

Bioceramics for Hip Joints: The Physical Chemistry Viewpoint

Pezzotti

2014

Materials

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Which intrinsic biomaterial parameter governs and, if quantitatively monitored, could reveal to us the actual lifetime potential of advanced hip joint bearing materials? An answer to this crucial question is searched for in this paper, which identifies ceramic bearings as the most innovative biomaterials in hip arthroplasty. It is shown that, if in vivo exposures comparable to human lifetimes are actually searched for, then fundamental issues should lie in the physical chemistry aspects of biomaterial surfaces. Besides searching for improvements in the phenomenological response of biomaterials to engineering protocols, hip joint components should also be designed to satisfy precise stability requirements in the stoichiometric behavior of their surfaces when exposed to extreme chemical and micromechanical conditions. New spectroscopic protocols have enabled us to visualize surface stoichiometry at the molecular scale, which is shown to be the key for assessing bioceramics with elongated lifetimes with respect to the primitive alumina biomaterials used in the past.

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“…Goldman et al, 23 Morikawa et al 24 and Shan et al 25 all considered the vacancies to be located next to the dopant species, whereas Komyoji et al 26 and Veal et al 27 reported the vacancies to be associated with the zirconium ion.…”

Section: Coordinationmentioning

confidence: 99%

Co-doping of scandia–zirconia electrolytes for SOFCs

et al. 2007

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Scandia stabilised zirconias offer much better electrical performance than conventional yttria stabilised materials; however, the limited availability and high cost of scandia have generally limited interest in its application in fuel cells. Political and economic changes over the last decade have significantly enhanced scandia's availability, rendering it worth considering for commercial application, even though there is still some uncertainty about its ultimate market price. A small addition of 2 mol% yttria to scandia stabilised zirconia results in stabilisation of the cubic phase and so avoids the major phase changes that occur on thermal cycling of scandia substituted zirconias, which might be expected to be detrimental to long term electrolyte stability. This addition of yttria does slightly impair the electrical conductivity of the scandia stabilised zirconia, although this can be reversed by further addition of ceria. Samples which are cubic throughout the studied temperature range basically show two linear conductivity regions in Arrhenius conductivity plots. A key observation is that the low temperature activation energy decreases and the high temperature activation energy increases as yttrium content increases and scandium content decreases. This correlates with the strength of short-range order as indicated by neutron and electron diffraction studies. Although scandia substitution increases conductivity and decreases high temperature activation energy, it also increases the tendency to short-range ordering at lower temperatures, resulting in a significant increase in activation energy for conduction. This is attributed to the ionic size of the Sc ion which favours a lower coordination number than that associated with ideal fluorite phases. It should also be realised that Zr, which has a similar size to Sc, also prefers a lower coordination number than is ideal for fluorite hence driving the tendency for short-range order in zirconia fluorites.

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Local Structures Around Y Atoms in Y<sub>2</sub>O<sub>3</sub>-Stabilized Tetragonal ZrO<sub>2</sub>

Cited by 37 publications

References 0 publications

Adhesion at metal–ZrO2 interfaces

Adhesion at metal–ZrO2 interfaces

Bioceramics for Hip Joints: The Physical Chemistry Viewpoint

Co-doping of scandia–zirconia electrolytes for SOFCs

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