材料期刊网

在NH4Cl助熔剂的掺杂下,采用高温固相法制备了CaMoO4∶Eu3+红色荧光粉.用热分析仪(TG-DSC)对样品的最佳合成温度进行了研究;用X射线粉末衍射(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)和激光拉曼光谱(LRS)表征了晶体的内部结构和表面形貌;用荧光光谱仪对晶体的发光效果进行了检测.结果表明,反应物在800 ℃即可形成晶体,合成产物为纯净的CaMoO4晶体,无杂相,结构稳定,颗粒呈球形,簇生,粒径约为5/7μm;激发光谱主要由一个位于200~350nm的O2-→Eu3+和O2-→Mo6+电荷迁移带、395nm处的7F0→5L6跃迁和465nm处的7F0→5D2跃迁两条尖峰构成,发射光谱由位于580~720nm的系列尖峰构成,其中强度最大的发射峰位于615nm处,属于Eu3+的5D0→7F2跃迁.当助熔剂的相对加入量为4％(摩尔分数)时,样品的发光效果最好,此时,Eu3+的最佳含量为0.06.

The CaMoO4∶Eu3+ phosphors were synthesized by the high-temperature solid-state reaction method with NH4Cl flux.The optimum synthesis temperature of the powders was studied by using a thermal analyzer (TG-DSC).The internal structures and the surface topographies were tested by X-ray powder diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR) and laser Raman spectroscopy.The luminescence of the crystal was detected by fluorescence spectrometer.The results show that the synthesis temperature of the crystal is 800 ℃.The powders are pure CaMoO4 crystal and have the stable structure.The particles are spherical clusters and the size is about 5/7 μm.The excitation spectrum is mainly composed by a charge transfer band from 200 to 350 nm of O2-→Eu3+ and O2-→Mo6+ and two peaks at 395 nm of 7F0→5L6 and 465 nm of 7F0→5D2.The emission spectrum is composed of a series of peaks from 580 to 750 nm.The main peak is at 615 nm due to the 5D0→7F2 transition of Eu3+.The luminescence of phosphors is the best when the relative of the flux is 4mol%.The best content of Eu3+ is 0.06.