Institute of Physics, ASCR, Prague, Praha 8, Czech Republic.
J Phys Condens Matter. 2010 Nov 10;22(44):445902. doi: 10.1088/0953-8984/22/44/445902. Epub 2010 Oct 22.
We investigated ceramics samples of solid solutions of PbFe(2/3)W(1/3)O(3)-[PbZr(0.53)Ti(0.47)O(3)](1 - x) (PFW(x)-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 PFW(x)-PZT(1 - 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 PFW(x)-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 PFW(x)-PZT(1 - x) thin films is not an intrinsic property, but probably an effect of electrodes, interlayers, grain boundaries or second phases presented in polycrystalline thin films.
我们通过宽带介电谱、差示扫描量热法和 SQUID 磁强计研究了PbFe(2/3)W(1/3)O(3)-[PbZr(0.53)Ti(0.47)O(3)](1 - x)（PFW(x)-PZT(1 - x)，x = 0.2 和 0.3）固溶体的陶瓷样品。我们没有证实 Kumar 等人的观察结果（2009 J. Phys.：Condens. Matter 21 382204），他们报告说在磁场高于 0.5 T 时，多晶 PFW(x)-PZT(1 - x)薄膜中铁电极化可逆抑制。我们没有观察到任何随外磁场变化的铁电极化，磁场高达 3.2 T。Pirc 等人（2009 Phys. Rev. B 79 214114）开发了一种理论，解释了报道的 PFW(x)-PZT(1 - x)中的大磁电效应，考虑到系统的弛豫铁电和弛豫铁电性质。我们的数据在 x = 0.2 和 0.3 的样品中分别在 525 K 和 485 K 以下揭示了经典铁电性质。此外，观察到顺磁行为一直持续到 4.5 K，而不是之前报道的弛豫磁行为。似乎报道的 PFW(x)-PZT(1 - x)薄膜中铁电极化的关闭不是固有特性，而是可能是多晶薄膜中存在的电极、层间、晶界或第二相的影响。
