烧结温度对钛酸钡/铁酸钴陶瓷性能影响

Effect of Sintering Temperature on Properties of Barium Titanate/Cobalt Ferrite Ceramics

铁电/铁磁复合材料由于其铁电相与铁磁相之间存在相互耦合作用,在存储器,传感器,换能器等方面具有广阔的应用前景。本文采用水热法制备了钛酸钡/铁酸钴陶瓷,研究了烧结温度对陶瓷晶体结构、表面形貌、电性能、磁性能以及磁电耦合性能的影响。结果表明:陶瓷主晶相为钛酸钡和铁酸钴,无其他杂相,且结晶度较好;陶瓷表面较为平整、孔洞较少,晶粒分布均匀,平均晶粒尺寸约为1.2μm;烧结温度为1200℃时,剩余极化强度最大,为11.83μC/cm^2,烧结温度为1300℃时,剩余极化强度最小,仅为049μC/cm^2;烧结温度为1250℃时,漏电流密度比其它样品小两个数量级;烧结温度为1250℃的陶瓷具有最大的介电常数和最小的损耗;烧结温度为1200℃时陶瓷的剩余磁化强度最小,为6.03 emu/g,烧结温度为1300℃时所得陶瓷的剩余磁化强度最大,为37.64 emu/g,且在外场(2mT)作用下剩余极化强度的相对变化量最大(34.69%),表现出一定的磁电耦合特性。

Ferroelectric/ferromagnetic composite materials have broad application prospects in memory, sensor, transducer and other aspects due to thecouplingbetween ferroelectric and ferromagnetic. Barium titanate/cobalt ferrite ceramics were prepared by hydrothermal method. The effects of sintering temperature on crystal structure, surface morphology, electrical properties, magnetic properties and magnetoelectric coupling properties of composite ceramics were studied. The results showed that the composite ceramics were barium titanate and cobalt ferrite with no other heterophase, good crystallinity simultaneously.The surface of composite ceramics was relatively flat with fewer holes and uniform grain distribution, the average grain size was about 1.2 μm. When sintering temperature was 1200 ℃, residual polarization intensity was the largest, 11.83 μC/cm^2. At 1300 ℃, residual polarization intensity was the smallest, only 049 μC/cm^2.At 1250 ℃, the leakage current density was two orders of magnitude smaller than other samples. The sample was sintered at 1250 ℃ had the maximum dielectric constant and dielectric loss minimum. At 1200 ℃, the remnant magnetization of the ceramic was minimum(6.03 emu/g). The residual magnetization of the samples obtained at sintering temperature of 1300 ℃ was the largest, which was 37.64 emu/g, and the residual polarization of the relative variation was maximum(34.69%) at the action of applied field of 2 mT, the ceramics had some magnetoelectric coupling characteristics.