Determination of tetragonal-cubic phase boundary of ZrRO (R = Nd, Sm, Y, Er and Yb) BY Raman scattering

Yashima, Masatomo; Ohtake, Katsuya; Kakihana, Masato; Arashi, H.; Yoshimura, Masahiro

doi:10.1016/0022-3697(95)00085-2

Cited by 206 publications

(168 citation statements)

References 32 publications

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“…All the samples were tetragonal and there was no trace of either the monoclinic or the cubic zirconia phases [20]. Raman spectroscopy confirmed the tetragonal nature for all the composition [21,22] and also in the case of sintered pellets, the patterns exhibit the (002)/{200) split as shown in Fig.1(a). The crystallite size estimated from the width of the (004)t/(400)t peaks is shown in Fig.2.…”

Section: Resultsmentioning

confidence: 52%

Fracture toughness of t’ ZrO2 stabilised with MO1.5 (M =Y, Yb & Gd) for thermal barrier application

Loganathan

Gandhi

2011

Trans Indian Inst Met

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Thermal Barrier coatings (TBC's) protect the gas turbine blades at high temperature exposure. The t' phase is metastable and slowly transforms to the high-temperature equilibrium state consisting of tetragonal (t) and cubic (c) during high temperature exposure. A comparative study of the phase stability and fracture toughness of monolithic Y, Yb and Gd stabilised zirconia with composition 8 mol%MO 1.5 was studied. Powders were prepared by co-precipitation method with crystallite size ~15 nm. Pressureless sintering, Spark plasma sintering (SPS) at 1250°C for 10 min was carried out to produce compacts with >96% relative density for fracture toughness measurements XRD and Raman studies revealed the the initial phase was t'. After sintering, no spontaneous monoclinic phase formed during cooling. The fracture toughness of the sintered pellets of different composition was measured. The results were analysed in terms of the effect of phase constitution on fracture toughness. The role of ferroelastic toughening in these materials was explored.

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Section: Resultsmentioning

confidence: 52%

Fracture toughness of t’ ZrO2 stabilised with MO1.5 (M =Y, Yb & Gd) for thermal barrier application

Loganathan

Gandhi

2011

Trans Indian Inst Met

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“…Although this phase is metastable, it can be stabilized by the addition of another cation in the structure, mainly yttrium, but also magnesium, calcium, gadolinium, and cadmium; moreover, the concentration of the cation plays an important role. [6][7][8][9][10][11] In the literature, many studies have centered on the local environment of the stabilizing ion by means of electron paramagnetic resonance (EPR). [12][13][14] Interestingly, doped ZrO 2 was rarely considered as a potential material for its electronic properties.…”

Section: Introductionmentioning

confidence: 99%

Manganese‐Doped Zirconia Nanocrystals

et al. 2008

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In recent theoretical work, it was predicted that transition-metal-doped zirconia (ZrO2) can be ferromagnetic at room temperature with a dependence on the metal dopant and its oxidation state and concentration.[1] For experimental verification of these predictions, manganese-doped ZrO2 nanoparticles were synthesized. The synthesis was achieved by the benzyl alcohol route, which led to high-quality nanocrystals with uniform size and shape. The obtained particles present a homogeneous distribution of the magnetic ion. The crystallographic phase was studied by XRD, electron diffraction, and high-resolution TEM. The doping efficiency was determined at the macroscopic level by chemical analysis and at the nanoscale level by electron energy loss spectrometry. The local structure of the manganese ions in the ZrO2 matrix was characterized by electron paramagnetic resonance. Finally, the magnetic properties of the obtained nanocrystals were investigated by susceptibility measurements

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“…However, this technique is unsuitable for the characterization of very small particles due to the extensive broadening of Bragg reflections. Also, this technique is not very sensitive to transitions which involve displacement of oxygen [4]. The characterization techniques based on the crystal symmetry, such as the Raman spectroscopy can detect crystallographic distortions and defects at the molecular level [5].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Structural Characterization of Nanocrystalline Batio3 at Various Calcination Temperatures

Fuentes

Céspedes

Muñoz

et al. 2013

J. Chil. Chem. Soc.

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Barium titanate (BaTiO 3 ) powders with particle sizes about 50 nm in diameter were synthesized using a hydrothermal route. The powders were characterized using various experimental techniques such as XRD, TEM and Raman spectroscopy, and they showed a good crystallinity and homogeneity without heat treatments. Also, Raman spectra showed the presence of the tetragonal phase. In addition, various calcination treatments were made to BaTiO 3 powders with the purpose to improve their ferroelectric properties. In general, calcination treatments improved the crystallinity and homogeneity of the samples considerably but did not modify the internal structure of the BaTiO 3 , which was observed in the Raman spectra. On the other hand, from theoretical calculations were established that the cubic phase should be better dielectric in comparison with the tetragonal phase, but this latter would have better optical properties. However, experimental evidences are indicative that the cubic phase would predominate in the synthesis of the compound.

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Determination of tetragonal-cubic phase boundary of ZrRO (R = Nd, Sm, Y, Er and Yb) BY Raman scattering

Cited by 206 publications

References 32 publications

Fracture toughness of t’ ZrO2 stabilised with MO1.5 (M =Y, Yb & Gd) for thermal barrier application

Fracture toughness of t’ ZrO2 stabilised with MO1.5 (M =Y, Yb & Gd) for thermal barrier application

Manganese‐Doped Zirconia Nanocrystals

Synthesis and Structural Characterization of Nanocrystalline Batio3 at Various Calcination Temperatures

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