resumo
We investigated ceramics samples of solid solutions of [PbFe2/3W1/3O3](x)-[PbZr0.53Ti0.47O3](1-x) (PFWx-PZT(1-x), x = 0.2 and 0.3) by means of broad-band dielectric spectroscopy, differential scanning calorimetry and SQUID magnetometry. We did not confirm the observations of Kumar et al (2009 J. Phys.: Condens. Matter 21 382204), who reported on reversible suppression of ferroelectric polarization in polycrystalline PFWx-PZT1-x thin films for magnetic fields above 0.5 T. We did not observe any change of ferroelectric polarization with external magnetic fields up to 3.2 T. Pirc et al (2009 Phys. Rev. B 79 214114) developed a theory explaining the reported large magnetoelectric effect in PFWx-PZT(1-x), taking into account relaxor magnetic and relaxor ferroelectric properties of the system. Our data revealed classical ferroelectric properties below 525 K and 485 K in samples with x = 0.2 and 0.3, respectively. Moreover, paramagnetic behavior was observed down to 4.5 K instead of previously reported relaxor magnetic behavior. It seems that the reported switching-off of ferroelectric polarization in PFWx-PZT(1-x) thin films is not an intrinsic property, but probably an effect of electrodes,
palavras-chave
SINGLE-CRYSTALS; FERROELECTRIC CERAMICS; DISPERSION
categoria
Physics
autores
Kempa, M; Kamba, S; Savinov, M; Marysko, M; Frait, Z; Vanek, P; Tomczyk, M; Vilarinho, PM
nossos autores
Monika Malgorzata Tomczyk
Estudante de doutoramento
Paula Maria Lousada Silveirinha Vilarinho
Vice-Diretoragradecimentos
The authors acknowledge the financial support of the Czech Science Foundation (project no. 202/09/0682) and Czech Academy of Sciences (AVOZ10100520). We also thank M Alexe for drawing our attention to the magnetic properties of Pt electrodes.