Co0.1Cu0.9Fe2O4 (CCFO) and Ba0.8Sr0.2TiO3 (BST) particles were respectively prepared by chemical coprecipitation and hydrothermal method, then CCFO/BST composite liquid was synthesized by distributing surface modified CCFO and Ba0.8Sr0.2TiO3 particles into insulating silicone oil. Effects of volume fraction (ϕv = 1%, 2%, 5% and 10%) on the microstructure, dielectric, ferroelectric and magnetoelectric coupling effect were comparatively investigated. XRD showed that the pure phase of CCFO and BST particles was successfully prepared. CCFO/BST composite particle shows ferromagnetic behavior due to the contribution of magnetic phase CCFO. The dielectric constant of CCFO/BST composite liquid is about 1/25 of the composite particles, and the dielectric constant value of the composite liquid decreases with increasing the volume fraction because the permittivity of silicone oil is far smaller than that of CCFO/BST composite particles. The relative change of dielectric constant of composite liquid under the action of external magnetic field is greater than that of composite particle due to its mobility of particles in liquid. The values of remnant polarization (Pr), coercive field (Ec) and leakage current of CCFO/BST composite liquid increase monotonically with increasing volume fraction, while excessive volume fraction may result in abnormal phenomenon because of the agglomeration of particles. Magnetic field-induced chain structure of the composite liquid has been observed under a light microscope at a magnification of 200. The maximal magnetoelectric (ME) coupling coefficient is about 89.78 V/(cm Oe), which is obtained in the CCFO/BST composite liquid when the volume fraction is 10%.

中文翻译：

---

体积分数对Co0.1Cu0.9Fe2O4/Ba0.8Sr0.2TiO3复合液磁电耦合效应的影响

采用化学共沉淀法和水热法分别制备Co0.1Cu0.9Fe2O4（CCFO）和Ba0.8Sr0.2TiO3（BST）颗粒，然后将表面改性CCFO和Ba0.8Sr0.2TiO3颗粒分散到绝缘材料中合成CCFO/BST复合液硅油。比较研究了体积分数（φv = 1%、2%、5%和10%）对微观结构、介电、铁电和磁电耦合效应的影响。XRD表明成功制备了CCFO和BST颗粒的纯相。由于磁相 CCFO 的贡献，CCFO/BST 复合颗粒表现出铁磁行为。CCFO/BST复合液体的介电常数约为复合颗粒的1/25，由于硅油的介电常数远小于CCFO/BST复合颗粒的介电常数，因此复合液体的介电常数值随着体积分数的增加而降低。由于复合颗粒在液体中的流动性，复合液体在外磁场作用下介电常数的相对变化大于复合颗粒。CCFO/BST复合液体的剩余极化（Pr）、矫顽力（Ec）和漏电流值随着体积分数的增加而单调增加，而体积分数过大可能会因颗粒团聚而导致异常现象。在放大倍数为 200 的光学显微镜下观察到复合液体的磁场诱导链结构。