Study of the Dielectric Properties of the Perovskite LaMn_0.5Co_0.5O_3–δ

Abstract

Polycrystalline samples of the charge ordered mixed oxide LaMn 0.5 Co 0.5 O 3Ϫδ (T CO ϭ 400 K) have been prepared by the nitrate decomposition method. These samples are biphasic, according to XRPD, and except one, oxygen defficient (δ ϳ 0.04-0.05). The study of the dielectric properties of these samples reveal that LaMn 0.5 Co 0.5 O 3Ϫδ displays a high dielectric constant, specially at room temperature and low frequencies. This εЈ r is seen to be strongly dependent on the particle size and not so much on the oxygen defficiency and the best properties are found in the sample with biggest particle size (φ ϭ 7 μm) for which εЈ r (300 K) ϳ 10 5 up to

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