预烧温度和烧结温度对YCaZrVIG铁氧体性能的影响

Effect of calcining and sintering temperature on the properties of YCaZrVIG ferrites

用传统氧化物法制备了组分为Y2.3Ca0.7Zr0.3V0.2Fe4.5-δO12(δ=0.05)的石榴石型铁氧体(简称YCaZrVIG)。用XRD、SEM对样品进行物相和微结构表征。研究了预烧温度和烧结温度对YCaZrVIG铁氧体物相组成、烧结性能、微观结构及电磁性能的影响。结果表明,烧结后的YCaZrVIG铁氧体均为单相石榴石结构;适当降低预烧温度可降低烧结温度,提高烧结体的密度,降低介电损耗;随烧结温度的升高,样品的体积密度、介电常数和剩磁均先上升后趋于稳定,矫顽力则是先大幅度下降后上升,而介电损耗在某一烧结温度以下相对稳定,一旦超过该烧结温度将显著增大。1100℃预烧、1350℃烧结时,YCaZrVIG铁氧体的结构致密,平均晶粒尺寸约7μm,综合性能较佳,ε=14.6,tanδε=2.4×10-4,Br=58mT,Hc=64A/m,μ0Ms=163mT,TC>200℃。

Garnet ferrites with composition of Y2.3Ca0.7Zr0.3V0.2Fe4.5-δO12（δ=0.05） （YCaZrVIG） were prepared by conventional oxide ceramic method. The phase formation and microstructure were analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, respectively. The influences of calcining and sintering temperature on phase compositions, sintering properties, microstructures and electromagnetic properties of YCaZrVIG ferrites were investigated. The results indicated that the sintered YCaZrVIG ferrites are single phase with garnet structure and the adequate decrease of calcining temperature can lower the sintering temperature, increase the sample＇s density and decrease dielectric loss. With increase of sintering temperature, bulk density, dielectric constant and remanence of the samples increase first and then tend to be stable, and coercivity decreases significantly and then increases. But dielectric loss keeps stable before a certain sintering temperature and increases obviously once over the sintering temperature. When the YCaZrVIG ferrite is calcined and sintered at 1100℃ and 1350℃, respectively, it has compact structure with average grain size about 7μm and optimal properties as： ε=14.6, tanδ=2.4×10^-4, Br=58mT, Hc=64A/m,μoMs=163mT, Tc〉200℃.