Ca2+掺杂对γ-Ce2S3红色色料的结构及性能的影响

Structure and Properties of γ-Ce2S3 Red Pigment with Ca2+ Doping

以CeO2为铈源, CaCO3为离子掺杂源, CS2为硫源,采用气-固相反应法,在硫化制度900℃硫化150 min时制得Ca2+离子掺杂的γ-Ce2S3红色色料。系统研究了不同的Ca, Ce摩尔比(nCa/nCe=0~0.5)对γ-Ce2S3的物相组成、晶体结构、呈色性能及温度稳定性的影响。研究结果表明:当未掺入Ca2+时,所得样品为纯α相,当nCa/nCe=0.1时,为α相与γ相共存;而当nCa/nCe=0.2~0.5时,α相已完全转变为γ相,并产生少量的CaS,且随着掺杂量的增大,γ-Ce2S3的晶胞参数逐渐减小,产生的CaS含量则略有增加,说明部分Ca2+成功进入晶格并形成固溶体,另有少量Ca2+则与S2-结合形成CaS;随着nCa/nCe增加,所合成样品的色调逐渐由暗红色向红色再向橙红色转变,且当nCa/nCe=0.4时,样品的红度值a*达到最高(L*=31.75,a*=24.50,b*=16.01)。将该组分色料在空气气氛中490℃保温10 min后仍以γ相稳定存在,表明通过Ca2+离子的掺杂,填补γ-Ce2S3晶格空位并形成固溶体,有利于稳定其晶格,从而使γ-Ce2S3的温度稳定性由350℃提升至490℃。

Ca2+dopedγ-Ce2S3 red pigments were success fully prepared by gas-solid reaction method at 900℃for 150 min using CeO2,CaCO3 and CS2 as raw materials.The effects of molar ratio of Ca and Ce(nCa/nCe=0~0.5)on the phase composition,crystal structure,color performance and temperature stability ofγ-Ce2S3 were systematically investigated.The results showed that onlyα-Ce2S3 could be found without doping Ca.When the molar ratio of nCa/nCe was 0.1,bothα-Ce2S3 andγ-Ce2S3 could be observed simultaneously.Increasing the molar ratio of nCa/nCe to 0.2~0.5,α-Ce2S3 was transformed toγ-Ce2S3 completely,along with a small amount of CaS.In the range molar ratio of nCa/nCe from 0.2 to 0.5,it could be found that the lattice parameters ofγ-Ce2S3 gradually decreased and the content of CaS phase increased slightly with increasing Ca content,indicating that a part of Ca2+entered into the lattice ofγ-Ce2S3 successfully and formed solid solution,and a small amount of Ca2+was combined with S2-to form CaS.Besides,it could also be observed that the hue of the synthesized samples gradually changed from dark-red tored and then to orange-red with the increasing of Ca content.When the molar ratio of nCa/nCe was further increased to 0.4,the red value(a*)was up to a maximum(L*=31.75,a*=24.50,b*=16.01).This composition still presented theγphase after heat treatment at 490℃for 10 min in air.It showed that the doping of Ca2+filled the internal vacancies ofγ-Ce2S3 and formed solid solution,which was beneficial to the stability of its lattice,thus improving the temperature stability ofγ-Ce2S3 from 350 to 490℃.