Effect of Manganese (II) Oxide on microstructure and ionic transport properties of nanostructured cubic zirconia

Defective MnxZr1–xO2 Solid Solution for the Catalytic Oxidation of Toluene: Insights into the Oxygen Vacancy Contribution

“…21 It is generally accepted that the replacement of the smaller cation Zr 4+ (ionic radius = 0.84 Å) with the larger cation Mn 2+ (ionic radius = 0.96 Å) could lead to the lattice expansion. 22,23 However, the obvious reduction of cubic lattice parameter was noticed in the doped samples, and the lattice parameter diminished from 5.087 Å (Mn 0.05 Zr 0.95 O 2 ) to 5.076 Å (Mn 0.3 Zr 0.7 O 2 ) with increasing doping content. Indeed, the appearance of oxygen vacancy will result in lattice contraction and parameter reduction, as discussed in the literature.…”

“…Considering that Mn doping can induce the significant change of zirconia crystal phase, the lattice parameter (5.09 Å) of the metastable c-ZrO 2 is used to represent the parameter of the undoped ZrO 2 sample . It is generally accepted that the replacement of the smaller cation Zr 4+ (ionic radius = 0.84 Å) with the larger cation Mn 2+ (ionic radius = 0.96 Å) could lead to the lattice expansion. , However, the obvious reduction of cubic lattice parameter was noticed in the doped samples, and the lattice parameter diminished from 5.087 Å (Mn 0.05 Zr 0.95 O 2 ) to 5.076 Å (Mn 0.3 Zr 0.7 O 2 ) with increasing doping content. Indeed, the appearance of oxygen vacancy will result in lattice contraction and parameter reduction, as discussed in the literature. − It is also proven that the substitution by the heteroatoms, of which the valence state is lower than that of the host atoms, can induce the appearance of the negatively charged defects (Mn Zr ″ ) and oxygen vacancies ( V O •• ) with a positive charge according to the Kroger–Vink notation: − Therefore, a possible reason for the decrease in lattice parameter can be attributed to the creation of oxygen vacancy in Mn x Zr 1– x O 2 catalysts.…”

Exploration of atomic interfaces with inherent oxygen vacancies in zirconia for toluene oxidation

“…In fact, the lattice contraction or expansion is determined by the competition between the cation radius change and the formation of oxygen vacancies. 17,18 In general, a substitution cation with a larger radius could lead to lattice expansion and a larger unit cell volume, but vacancy generation would induce lattice contraction and parameter reduction. 5,19 As a consequence, with the increase in the Ce concentration in zirconia, the oxygen content in the lattice diminished, vacancy defects rose, and the modication of steric effects on lattice parameters gradually became negligible.…”

As-Sintered Manganese-Stabilized Zirconia Ceramics with Excellent Electrical Conductivity

“…Many researchers have paid attention to the conductivity property of Mn-doped YSZ [14,15], and confirmed that Mn ion can considerably affect the conductivity of YSZ. Kim [16] found that with the addition of Mn 2 O 3 in YSZ, the conductivity increase to 0.5 mS/cm at 600 • C. Lei [17] reported that 11ScSZ-2Mn 2 O 3 ceramics with the cubic structure possesses the conductivity 4 mS/cm at 600 • C. Recently, researchers have studied the conductivity of 30 mol/% MnO doped ZrO 2 powders with the method of mechanical alloying and found that the intermediate temperature conductivity can be 0.4 mS/cm at 550 • C [18].…”