Synthèse et caractérisation d'une série de titanates pérowskites isotypes de [CaCu3](Mn4)O12

Bochu, B.; Deschizeaux, M.N.; Joubert, J.C.; Collomb, A.; Chenávas, J.; Marezio, M.

doi:10.1016/0022-4596(79)90235-4

Cited by 226 publications

(124 citation statements)

References 10 publications

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“…It has a high and relatively temperature independent low-frequency dielectric constant over a wide temperature range between 100 K and 600 K. However, below 100 K the value drops abruptly by almost three orders of magnitude, an effect that is not accompanied by a long-range structural phase transition. 1,2,3 The crystal structure of CCTO (s.g. Im3) 4 is shown in Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependent total scattering structural study of CaCu₃Ti₄O₁₂

Božin¹,

Petkov²,

Barnes³

et al. 2004

J. Phys.: Condens. Matter

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X-ray and neutron powder diffraction data as a function of temperature are analyzed for the colossal dielectric constant material CaCu3Ti4O12. The local structure is studied using atomic pair distribution function analysis. No evidence is found for enhanced oxygen displacement parameters suggesting that short-range octahedral tilt disorder is minimal. However, an unusual temperature dependence for the atomic displacement parameters of calcium and copper is observed. Temperature dependent modeling of the structure, using bond valence concepts, suggests that the calcium atoms become underbonded below approximately 260 K, which provides a rationale for the unusually high Ca displacement parameters at low temperature.

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Section: Introductionmentioning

confidence: 99%

Temperature dependent total scattering structural study of CaCu₃Ti₄O₁₂

Božin¹,

Petkov²,

Barnes³

et al. 2004

J. Phys.: Condens. Matter

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“…As reported in previous reports, CaCu 3 Ru 4 O 12 (x = 0) exhibits two kinds of electrical current paths (Figure 8a). The first one relies on the Ru-O network (I Ru ), while the second relies on Cu 2+ (I Cu ).…”

Section: Resultsmentioning

confidence: 56%

“…The lattice constant, which was calculated from the 2θ angles corresponding to (n00) planes, is plotted as a function of x in Figure 3. The lattice constant systematically decreases from 7.428 Å for CaCu 3 4+ , even if the size reduction effect would be larger without the charge transfer. By contrast, the influence of such a charge transfer on the electrical transport and resistivity would be dramatically large.…”

Section: Methodsmentioning

confidence: 99%

“…In our preliminary experiment, Ru sublimation and formation of second phases such as CaRuO 3 were confirmed after calcination at 1000 • C without the surroundings. In addition, although the exact solubility limit of Mn at the Ru-site obtained with a synthesis at atmospheric pressure is unknown, it was not possible to synthesize CaCu 3 X-ray diffraction (XRD) of the bulk samples was carried out using a standard diffractometer with CuKα radiation, in the 2θ-θ scan mode (Rigaku SmartLab, Tokyo, Japan). The morphology of the bulk samples was observed using a field emission scanning electron microscope (FE-SEM; JEOL JSM-6335FM, Tokyo, Japan).…”

Section: Methodsmentioning

confidence: 99%

“…A wide variety of cations can occupy the A-, B-and C-sites, and various partial substitutions are possible on each of these sites [1][2][3][4][5][6]. Many interesting properties have been found in these compounds, leading to potential applications in various fields.…”

Section: Introductionmentioning

confidence: 99%

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Element Strategy Using Ru-Mn Substitution in CuO-CaCu3Ru4O12 Composite Ceramics with High Electrical Conductivity

et al. 2017

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CaCu 3 Ru 4−x Mn x O 12 bulks with various substitution amounts x and sintering additive CuO (20 vol.%) were prepared, and the influence of x on the electrical conductivity in a wide temperature range (8-900 K) was investigated. Microstructural observations showed an enhancement of bulk densification upon Mn substitution. Although the resistivity increased with increasing x, the resistivity was as low as a few mΩcm even in the sample with x = 2.00, where half of Ru is substituted by Mn. This high conductivity despite the loss of Ru 4d conduction following the substitution is explained by the A-site (Cu 2+ ) conduction in CaCu 3 Ru 4−x Mn x O 12 . The thermopower of CaCu 3 Ru 4−x Mn x O 12 was found to be influenced by the substitution, and a sign inversion was observed in the substituted samples at low temperature. The partial substitution of Ru by Mn in CaCu 3 Ru 4 O 12 enables the reduction of the materials cost while maintaining good electrical conductivity for applications as a conducting device component.

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