Structural evolution of manganosite: Comparison of properties of nonstoichiometric manganese and iron monoxides

Gavarri, J.R.; Arabski, J.; Jasieńska, S.; Janowski, J.; Carel, C.

doi:10.1016/0022-4596(85)90268-3

Cited by 10 publications

(3 citation statements)

References 31 publications

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“…As indicated in Table 1, powder XRD analyses produced almost identical lattice parameters for the two samples and both are consistent with stoichiometric MnO (Gavarri et al 1985). Specimen 1 Table i.…”

Section: Specimen Characterizationsupporting

confidence: 68%

Pressure and temperature dependence of the elastic properties of synthetic MnO

Pacalo

Graham

1991

Phys Chem Minerals

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Abstract. The adiabatic elastic stiffness constants of synthetic single-crystal MnO were measured in this study using pulse superposition interferometry. Data were obtained up to 1.0 GPa in pressure and over the temperature range 273 to 473 K. As a result, we were able to determine the complete set of second-order stiffness moduli (C~]) and their pressure and temperature derivatives, as well as higher-order properties for selected modes. Relevant results for the adiabatic bulk modulus are: KS= 155.1 +0.8 GPa;(~Ks/~P)r=4.70+_0.13; and, (~KS/~T)v=-0.0203_+0.0009 GPa/K. Our results for the second-order moduli are generally consistent with the data from previous studies. However, relative to the estimated uncertainties, small and systematic discrepancies appear to characterize the data set. The available evidence indicates that the differences result from microstructural variations (in particular, microcracks and Mn30 4 inclusions) between the synthetic MnO specimens used in different investigations. The pure shear mode C44 exhibits anomalous soft-mode behavior with both temperature (the ambient derivative is positive) and pressure (the ambient derivative is negative). In both cases the C4~ data trends appear to primarily reflect the influence of Mn -Mn magnetoelastic interactions associated with the onset of a paramagnetic-antiferromagnetic (PM --> AFM) phase transition.

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Section: Specimen Characterizationsupporting

confidence: 68%

Pressure and temperature dependence of the elastic properties of synthetic MnO

Pacalo

Graham

1991

Phys Chem Minerals

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“…This is why many previous structural studies (Koch & Cohen, 1969;Cheetham, Fender & Taylor, 1971;Catlow & Fender, 1975;Gavarri, Carel & Weigel, 1979;Gavarri, Carel, Jasienska & Janowski, 1981;Gartstein, Mason & Cohen, 1986) have been performed on this material at high temperature or after quenching. It has been shown that the wfistites are characterized by various types of clustering of vacancies (I--l) and interstitial Fe In ions occupying the octahedral (octa) and tetrahedral (tetra) sites respectively of the NaC1 lattice with the general formula:…”

Section: Introductionmentioning

confidence: 99%

The commensurate (10/4) cluster model in quenched wüstite P''. New simulation of HREM direct images

Nihoul¹,

Gavarri²,

Carel³

1991

Acta Crystallogr Sect B

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In the case of non-stoichiometric quenched wfistite P" with the formula Fel-zO (z = 0.096), the defect structure is shown to consist most probably of clusters composed of ten vacancies and four interstitial Fe III ions. These clusters are in agreement with a long-range ordering (2.5X, 2.5X, 5)0, with some disorder in their local arrangement. The direct im~iges of the quenched phase P", previously obtained by various authors, are reinterpreted from a (10/4) cluster model: computer simulations have been carried out using this new model. The simulated images are in good agreement with the experimental images found in the literature.

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“…Empty points denote the values obtained for the model of the structure of simple defects (vac) without complexes (Stokłosa, 2012). As shown in Figure (Hed & Tannhauser, 1967a and (Fender & Riley, 1970), as well as by (Carel, 1982;Gavarri et al, 1985). (6:2) clusters, and the lowest -of (2:1) clusters.…”

Section: δGmentioning

confidence: 99%

Defect Complexes and Defect Clusters in Mn1-deltaO, Co1-deltaO and Ni1-deltaO Oxides Diagrams of the Concentrations of Point Defects

Stokłosa¹

2012

IJC

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The diagrams of the concentrations of point defects, determined for a series of temperatures, for the oxides: Mn 1-δ O, (1173-1830 K), Co 1-δ O (1223-1673 K) and Ni 1-δ O (1273-1673 K), whilst taking into consideration simple defects and defect clusters of type (2:1), (4:1), (6:2), are presented in this work. A new method was used for the calculations of the diagrams and the results of the studies of the deviation from the stoichiometry obtained by many authors were used in the calculations. The values of Go of the formation of the individual defects and clusters were determined; their temperature dependencies were also determined. The calculations show that in the studied oxides the maximal concentration of defect clusters is lower than the concentration of single-ionized cation vacancies. At the lowest temperatures studied, the concentration of clusters is comparable to the concentration of electroneutral vacancies. The ratio of these concentration decreases with the temperature increase. The presence of defect clusters only slightly decreases the concentration of cation vacancies. The ratio of the concentrations of defect clusters varies with the temperature. This ratio is different for the individual oxides.

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Structural evolution of manganosite: Comparison of properties of nonstoichiometric manganese and iron monoxides

Cited by 10 publications

References 31 publications

Pressure and temperature dependence of the elastic properties of synthetic MnO

Pressure and temperature dependence of the elastic properties of synthetic MnO

The commensurate (10/4) cluster model in quenched wüstite P''. New simulation of HREM direct images

Defect Complexes and Defect Clusters in Mn1-deltaO, Co1-deltaO and Ni1-deltaO Oxides Diagrams of the Concentrations of Point Defects

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