References of "Rivas-Murias, Beatriz"
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See detailThermoelectric properties of n-type Ca1-xDyxMn1-yNbyO3-delta compounds (x=0, 0.02, 0.1 and y=0, 0.02) prepared by spray-drying method
Muguerra, Hervé; Rivas-Murias, Beatriz; Traianidis, Maria et al

in Journal Of Alloys And Compounds (2011), 509(29), 7710-7716

We report the high temperature thermoelectric properties of Ca1-xDyxMn1-yNbyO3-delta (x = 0, 0.02, 0.1 and y = 0, 0.02) synthesized by spray-drying method. A maximum power factor (PF) value of 2.65 mu WK ... [more ▼]

We report the high temperature thermoelectric properties of Ca1-xDyxMn1-yNbyO3-delta (x = 0, 0.02, 0.1 and y = 0, 0.02) synthesized by spray-drying method. A maximum power factor (PF) value of 2.65 mu WK-2 cm(-1) is obtained at 1100 K for CaMn0.98Nb0.02O3-delta. This represents an improvement of about 75% with respect to undoped CaMnO3-delta sample at the same temperature. We also provide a complete structural characterization of the samples. (C) 2011 Elsevier B.V. All rights reserved. [less ▲]

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See detailMeasurement of dielectric properties at low temperatures: application to the study of magnetoresistive manganite/ insulating oxide bulk composites
Vanderbemden, Philippe ULg; Rivas-Murias, Beatriz; Lovchinov, Vassil et al

in Journal of Physics: Conference Series (2010), 253

In this paper, we report low temperature dielectric measurements of bulk composite electroceramic samples containing a colossal magnetoresistive (CMR) manganite phase (La0.7Ca0.3MnO3 [abbreviated LCMO ... [more ▼]

In this paper, we report low temperature dielectric measurements of bulk composite electroceramic samples containing a colossal magnetoresistive (CMR) manganite phase (La0.7Ca0.3MnO3 [abbreviated LCMO]) and an insulating phase (Mn3O4). Details of the experimental system are given and possible experimental artefacts due to moisture are outlined. For a LCMO volume fraction of ~ 16%, the permittivity of the LCMO/ Mn3O4 composite at T = 50 K is found to be much higher than that of pure Mn3O4 and magnetic field dependent. This effect is related to an extrinsic space charge polarization mechanism between the insulating phase (Mn3O4) and the conducting magnetoresistive phase (LCMO). [less ▲]

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See detailImprovement of the thermoelectric properties of [Bi1.68Ca2O4-delta](RS)[CoO2](1.69) cobaltite by chimie douce methods
Muguerra, Hervé; Rivas-Murias, Beatriz; Traianidis, Maria et al

in Journal of Solid State Chemistry (2010), 183(6), 1252-1257

[Bi1 68Ca2O4 delta](RS)[CoO2](1 69) has been obtained by different chimie douce methods and uniaxially or isostatically pressed The influence of these parameters on the thermoelectric properties has been ... [more ▼]

[Bi1 68Ca2O4 delta](RS)[CoO2](1 69) has been obtained by different chimie douce methods and uniaxially or isostatically pressed The influence of these parameters on the thermoelectric properties has been investigated. Contrary to the Seebeck coefficient, which remains unchanged, the electrical conductivity is greatly modified In particular, spray-drying synthesis followed by uniaxial pressing results in an electrical conductivity two times larger than in the case of conventional solid state synthesis. Our results suggest that a narrow particle size distribution is beneficial to the thermoelectric properties of the layered compounds. The spray-drying technique seems to be promising to Improve the electrical conductivity of layered materials. Moreover, this method presents other advantages (homogeneous samples and less energetic processing) which could be interesting to the future manufacturing of thermoelectric devices (C) 2010 Elsevier Inc. All rights reserved [less ▲]

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See detailGrain boundary effects in bulk colossal magneto resistive (CMR) manganites and manganite/insulator composites: electrical and magnetic properties
Vanderbemden, Philippe ULg; Vertruyen, Bénédicte ULg; Ausloos, Marcel ULg et al

in Journal of Optoelectronics and Advanced Materials [= JOAM] (2009), 11(9), 1115-1121

In the first part of this paper, we discuss the effects of grain boundaries on the properties of bulk colossal magnetoresistive (CMR) manganites We compare the electrical resistivity and AC magnetic ... [more ▼]

In the first part of this paper, we discuss the effects of grain boundaries on the properties of bulk colossal magnetoresistive (CMR) manganites We compare the electrical resistivity and AC magnetic susceptibility of perovskite La-Ca-Mn-O samples with the same nominal stoichiometry but differing in their microstructure (i) a single grain sample, (ii) a sample containing two grains and (iii) a polycrystalline sample Emphasis is placed on information that can be deduced from the measurements in each case In the second part of the paper, we report the data measured on composite samples containing a CMR phase (La-Ca-Mn-O) and an insulating phase (Mn3O4) The results are discussed in the framework of percolation theory We show how the grain boundaries affect the electrical properties of these materials, and we highlight the crucial role of geometric (demagnetization) effects on the resistance vs magnetic field measurements [less ▲]

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