功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2012年
21期
2977-2980
,共4页
李意峰%曹丽云%黄剑锋%吴建鹏
李意峰%曹麗雲%黃劍鋒%吳建鵬
리의봉%조려운%황검봉%오건붕
铜酸镧%溶胶-凝胶法%La/Cu%分散剂%光学性质
銅痠鑭%溶膠-凝膠法%La/Cu%分散劑%光學性質
동산란%용효-응효법%La/Cu%분산제%광학성질
lanthanum cuprate%sol-gel process%La/Cu%dispersant%optical property
采用溶胶-凝胶法,以硝酸镧和硝酸铜为原料,在不同La/Cu物质的量比条件下合成了LazCuO4粉体。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和紫外-可见-近红外光谱(UV—Vis-Nir)对样品的物相组成、显微形貌以及光学性能进行了分析。结果表明,n(La)/n(Cu)比为化学计量比2:1时,可以制备出单一相的La2CuO4;n(La)/n(Cu)〈2:1时,产物含有CuO杂质相;n(La)/n(Cu)〉2:1时,含有La2O3杂质相。根据UV—Vis—Nir光谱分析,咒(La)/n(Cu)为2:1,所得La2CuO4的光学带隙为1.37eV,杂质相的产生使光学带隙减小。以抗坏血酸、葡萄糖为分散剂,有较好的分散效果,聚乙二醇作为分散剂时,出现团聚现象,相应的光学带隙分别为1.39、1.41和1.33eV。
採用溶膠-凝膠法,以硝痠鑭和硝痠銅為原料,在不同La/Cu物質的量比條件下閤成瞭LazCuO4粉體。利用X射線衍射儀(XRD)、掃描電子顯微鏡(SEM)和紫外-可見-近紅外光譜(UV—Vis-Nir)對樣品的物相組成、顯微形貌以及光學性能進行瞭分析。結果錶明,n(La)/n(Cu)比為化學計量比2:1時,可以製備齣單一相的La2CuO4;n(La)/n(Cu)〈2:1時,產物含有CuO雜質相;n(La)/n(Cu)〉2:1時,含有La2O3雜質相。根據UV—Vis—Nir光譜分析,咒(La)/n(Cu)為2:1,所得La2CuO4的光學帶隙為1.37eV,雜質相的產生使光學帶隙減小。以抗壞血痠、葡萄糖為分散劑,有較好的分散效果,聚乙二醇作為分散劑時,齣現糰聚現象,相應的光學帶隙分彆為1.39、1.41和1.33eV。
채용용효-응효법,이초산란화초산동위원료,재불동La/Cu물질적량비조건하합성료LazCuO4분체。이용X사선연사의(XRD)、소묘전자현미경(SEM)화자외-가견-근홍외광보(UV—Vis-Nir)대양품적물상조성、현미형모이급광학성능진행료분석。결과표명,n(La)/n(Cu)비위화학계량비2:1시,가이제비출단일상적La2CuO4;n(La)/n(Cu)〈2:1시,산물함유CuO잡질상;n(La)/n(Cu)〉2:1시,함유La2O3잡질상。근거UV—Vis—Nir광보분석,주(La)/n(Cu)위2:1,소득La2CuO4적광학대극위1.37eV,잡질상적산생사광학대극감소。이항배혈산、포도당위분산제,유교호적분산효과,취을이순작위분산제시,출현단취현상,상응적광학대극분별위1.39、1.41화1.33eV。
La2CuO4 crystallites were prepared via a sol-gel process using lanthanum nitrate and cupric nitrate as raw materials with different La/Cu molar ratios. The phase composition, microstructure and optical property of the as-prepared La2CuO4 powders were characterized by X-ray diffraction, scanning electron microscope and UV-Vis-NIR spectrophotometer. The results show that pure La2CuO4 crystallites can be obtained when La/Cu molar ratio corresponds with the stoichiometrie ratio (2 : 1). CuO or La2O3 impurity phase can be detected when the La/Cu molar ratio was lower or higher than the stoichiometric ratio. According to UV-Vis-NIR spec- tral analysis, the optical band gap was 1.37eV when La/Cu molar ratio was 2: 1, while it decreases along with the appearance of impurity phase. With ascorbic acid or ghlcose as dispersant, the dispersity of the producls was improved. Using polyethylene glycol as dispersant, the reunion phenomenon appears. And the correspond ing optical band gap was 1.39, 1.41 and 1.33eV, respectively.