Size and Charge Effects of Dopant M on the Unit‐Cell Parameters of Monoclinic Zirconia Solid Solutions Zr_0.98M_0.02O_{2 –δ} (M = Ce, La, Nd, Sm, Y, Er, Yb, Sc, Mg, Ca)

Abstract

The crystal structure of monoclinic phase [P2,/c, Z = 41 has been refined by the Rietveld analysis of X-ray powder diffraction data to studv the size and charge effects of dopant M"' on the m&-cell parameters of monoclinic Zr02-2 mol% MO,,,? solid solutions (n = 4 for M = Ce; II = 3 for M = La, Nd, Sm, Y, Er, Yb, SC ; and 12 = 2 for M = Mg and Ca). For trivalent dopant (n = 3), the unit-cell parameters a,,>, b,,,, c,, and unit-cell volume increase and p,,, decreases with an increase of dopant size. Unit-cell volume increases with increasing of dopant charge n.

Structural Changes of Scandia‐Doped Zirconia Solid Solutions: Rietveld Analysis and Raman Scattering

“…This observation indicates that the unit-cell parameters of m-ZrO 2 vary anisotropically with X. Such anisotropy in the change of the m-phase unit-cell parameters via ScO 1.5 doping is similar to those observed in both cases of thermal expansion [27][28][29][30] and doping of other oxides (such as YO 1.5 31 and CeO 22,28 . Reflecting this anisotropy, the rates of change for the unit-cell parameters with increasing X have the following relations:…”

“…1), which is consistent with the literature. 12,22 In the compositional region of X ‫ס‬ 2-6 mol%, the ZrO 2 -XScO 1.5 samples were a mixture of m-phase and t-phase. † † As-arc-melted spherical specimens of X ‫ס‬ 8 and 10 mol% were tetragonal and single phase, whereas powdered samples with the same compositions were a mixture of t-phase and m-phase, which indicates that some of the tetragonal single phase of the as-arc-melted specimen transformed to the monoclinic form during crushing and grinding for the preparation of the powdered samples for XRD study.…”

Hydrothermal Synthesis of Yttria-Stabilized Zirconia Nanocrystals with Controlled Yttria Content

“…The phase composition agrees with the phase diagram of bulk 8YSZ crystals. 28 Only the broad band between 500 and 620 cm −1 is observed for 10YSZ and 12YSZ, indicating the presence of the cubic phase with a significant amount of disordered oxygen vacancies. 24 Figure 11 shows the Y 2 O 3 content of the YSZ nanocrystals determined by EDS analysis of the powdered samples.…”

Phase equilibria in the refractory oxide systems of zirconia, hafnia and yttria with rare-earth oxides

“…In the series of phase diagrams, temperature of melting and solid-state transformations directly depends on the ratio between ionic radii of cations r Hf 4+ /r Ln 3+ . The solubility in the monoclinic phase, as a rule, does not exceed 2 mol%, and in the tetragonal it is less 179,[229][230][231] In the case of lanthanide oxides, the lattice parameters of monoclinic ZrO 2 solid solutions dissolving 2 mol%, Ln 2 O 3 , varies linearly with ionic radius of lanthanide (Fig. 6).…”