For comparison, an emission spectrum from a representative binary glass sample, (PbO)0.25(SiO2)0.75, is shown in Figure 8.4e-left. The reduced lead immediately forms alloy with platinum, which has a much lower melting point than platinum or lead and thus causes crucible leakage. See Chlorine: Hydrocarbons (references 1,4), See Fluorine: Miscellaneous materials (reference 1). The molecular formula identifies each type of element by its chemical symbol and identifies the number of atoms of each element found in one discrete molecule of the substance. Figure 8.3(a)–(d) shows the UV–visible optical absorption patterns of ternary (PbO)x[(Na2O)0.25(SiO2)0.75]1−x glasses with 0.10≤x≤0.25. β-PbO is obtained at temperatures higher than 486°C and α-PbO, at lower temperatures. 4(1) Restrictions, Annexes III & IV, EC Inventory, C&L Inventory, PIC, Pre-Registration process, Other, ROHS - Exemptions from Art. The tet-PbO elementary (unit) cell is presented in Fig. [7–9]. The electronic component depends on the pressure of oxygen; Bi addition creates n-type conductivity, whilst K dopant creates p-type conductivity. Substances Restricted in Toys, Directive 2009/48/EC, OJ L 170/1, 30 June 2009, last amended by Directive 2019/1929/EU, 20 November 2019, EU. If no EU harmonised classification and labelling exists and the substance was not registered under REACH, information derived from classification and labelling (C&L) notifications to ECHA under CLP Regulation is displayed under this section. There is a weak shoulder near the absorption edge for the sample corresponding to x=0.2 which has been attributed to the minor structural inhomogeneities present in the glass. The database represents a non-exhaustive list of such substances based on: 1) agents of risk groups 3 and 4 under Directive 2000/54/EC; 2) Table 3 of Annex VI to the CLP Regulation; 3) and Annex I of Directive 2004/37/EC. PbO occurs in two polymorphs: litharge having a tetragonal crystal structure, and massicot having an orthorhombic crystal structure. The type of uses and classifications may vary between different submissions to ECHA and for a full understanding it is recommended to consult the source data. The ‘Hazard classification’ and labelling section uses the signal word, pictogram(s) and hazard statements of the substance under the harmonised classification and labelling (CLH) as its primary source of information. Please upgrade your Internet Explorer to a newer version. If aluminium is present, the mixture explodes on heating (but the same is true if silicon is absent) [1]. Titanium is also oxidized violently on warming. Simpson, M. B. H., Kautsch. Owing to the significantly higher number of electrons and orbitals for Pb2+ ions compared with Na+ ions, strong spin–orbit interaction takes place which results in an increased transition probability for triplet to singlet transition. If generated, an InChI string will also be generated and made available for searching. Figure 8.4. If a substance is classified under multiple CLH entries, a link to the C&L Inventory is provided to allow users to view CLH information associated with the substance and no text is automatically generated for the InfoCard. This information is only displayed if the substance is well–defined, its identity is not claimed confidential and there is sufficient information available in ECHA’s databases for ECHA’s algorithms to generate a molecular structure. 2(b)(i) - Hazardous Agents, Cosmetic Products Regulation, Annex II - Prohibited Substances, EU Ecolabels - Restrictions for Hazardous Substances/Mixtures, IPPC - Industrial Emissions Directive, Annex II - Polluting Substances, IPPC, Annexes V, VI, VIII - Provisions relating to industrial plants, Packaging Waste Directive - Heavy Metals Concentration Level, Protection of Pregnant and Breastfeeding Workers Directive, Annex I+II, Physical, Biological and Chemical Agents & Processes and Work, ROHS Directive - Restricted Substances as per Art. Turning to the question of what possible surface relaxations or reconstructions may occur, we need to consider the topology and local chemical bonding since we have already determined that these surfaces are autocompensated (Principle 4) and insulating (Principle 2). Chemical Agents: Annexes I & II, Dir. The purpose of the information provided under this section is to highlight the substance hazardousness in a readable format. The most common precursors in use are [Pb(thd)2] and [PbEt4] with an O2 oxygen source; however, other precursors do exist. Lead balls are fed into a rotating steel drum. Use high purity platinum for the crucibles. The 112¯0 surface has been studied by low-energy-electron-diffraction and transmission electron diffraction (Schildbach and Hamza, 1992; Susnitzky and Carter, 1986), as well as by a variety of reflection techniques (Yao et al., 1989). 4(1) Restrictions, Annexes III & IV, Substances of very high concern identification, Recommendation for the Authorisation List, Getting started with EU chemicals legislation, Classification of substances and mixtures, Harmonised classification and labelling (CLH). The rather rigid and compact (almost spherical) structure with its hydrophobic surface, together with the lack of charge, generates a volatile compound that is soluble in organic solvents such as dichloromethane or acetone but insoluble in water. When orthorhomb-PbO is cooled rapidly, it may remain unchanged and continue to exist at low temperatures. Polluting Substances: Annex II, Directive 2010/75/EU on Industrial Emissions (IPPC), 17 December 2010, EU. We are one of the largest manufacturers of Red Lead in India also known as Lead Tetra Oxide or Red Oxide. The solid lines mark the surface unit cells. InfoCards are generated automatically based on the data available at the time of generation. A similar shoulder was also observed for many glasses containing heavy-metal oxide, as reported by Liu et al. Figure 8.4 shows the emission and excitation spectra for (PbO)x[(Na2O)0.25(SiO2)0.75]1−x glasses containing different amounts of PbO. We use cookies to help provide and enhance our service and tailor content and ads. Compound 59 was used as a precursor to deposit lead oxide thin films via LPCVD. 4.11. Decay curves corresponding to L-centre emissions for (PbO)x[(Na2O)0.25(SiO2)0.75]1−x glasses, having (A) x=0.1 and (B) x=0.25. The transfer number of Pb2+ is only 0.01 and the ionic conductivity is due entirely to oxygen [6,7]. 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As PbO is incorporated into the glass, Si–O–Si bonds get broken resulting in the formation of silicon structural units with non-bridging oxygen atoms, the negative charge present on it facilitating the excitation of its electron to the higher energy level. Lead(II) oxide, also called lead monoxide, is the inorganic compound with the molecular formula PbO. So, one can imagine the following scenario: if (i) some free PbO exists in the chemical batch loaded in a platinum crucible and (ii) the temperature of the crucible in the furnace is hotter at the upper segment, i.e. The latter form predominates if low current density is applied or cyclic polarization is prolonged. Hence, a similar rumpling relaxation is expected. 8.4 (left)). According to the annexes to the directive, storage areas and containers containing chemical substances or mixtures that are classified as hazardous according to the CLP Regulation (1272/2008/EC) must be marked and/or labeled.