PbO, Pb_3O_4の摩砕効果 : 塩基性炭酸鉛生成と光伝導の変化
スポンサーリンク
概要
- 論文の詳細を見る
Phase transformation of yellow orthorhombic PbO to red tetragonal form was confirmed by grinding at room temperature. The long time grinding in atmosphere converted the PbO powder into white lead, the basic lead carbonate, Pb_3(CO_3)_2(OH)_2 finally. The first reaction product in the nitrogen stream was not white lead, but lead oxy-carbonate, PbO. PbCO_3. Thus the effect of moisture was prevented well in this condition, though the carbonate formation was not avoided. The line profiles of the X-ray powder diffration patterns of the ground product are fairly sharp. The average size of the crystallites determined by the line breadths is about 200 Å in diameter, and this value agrees well with that of the electron microphotograph. The density of the white lead thus obtained is rather high compared with the ordinary one. The sharp line profiles must be due to the crystallization by constant grinding. Consequently it may be assumed that a quasiequilibrium state is established between the decomposition and the formation of white lead crystallites. Pb_3(CO_3)_2(OH)_2⇄<H_2O + CO_2>^<Decomposition by grinding> X-ray amorphous PbO When the Pb_3O_4 is converted into a mixture of white lead and α-PbO_2 by grinding in atmosphere the product turns dark brown. The photoconductivity measurement of the ground samples was carried out at their early stage of grinding in their visible and near infra-red region. Two new peaks appeared at 680mμ and 950mμ. The peak at 680mμ was largely affected by moisture and in some cases this peak was very high and overlapped the second lower 950mμ peak. The 680mμ peak will be attributed to the absorption of water molecules on the active site of the PbO surface, and the 950mμ peak to some lattice imperfection originated by grinding on the surface region of the PbO grains, respectively. The synthetic reaction of basic lead carbonate by grinding red PbO is explained on the basis of "active states"that appeared in the PbO grains by grinding.
- 社団法人日本材料学会の論文
- 1970-06-15
著者
関連論文
- 無定形珪酸鉱物の誘電現象
- 70SiO_2・15B_2O_3・15Na_2Oガラスの表面結晶化の現象 : 硼珪酸ナトリウムガラスの表面結晶化(I)
- PbO, Pb_3O_4の摩砕効果 : 塩基性炭酸鉛生成と光伝導の変化
- 火山ガラスの電気的性質と水熱反応性
- 3p-C-1 塩化スズ2水和物のラマン散乱
- Cu-Se系化合物の電気ならびに磁気性質 : 金属
- 水晶の二重反射 : X線電子線
- 1973年度日本結晶学会年会について
- 結晶成長と化学的特性記述
- 学術展示と研究所訪問について
- 結晶構造とエッチパタン
- 結晶と水
- 核磁気共鳴の窯業材料への応用
- 4.数種の珪酸塩ガラスおよび珪酸塩結晶の磨砕による変化について(研究発表講演要旨)
- 2p-D-1 結晶成長と格子不整
- タイトル無し