Lead telluride

Lead Telluride. Lead teUuride [1314-91 -6] PbTe, forms white cubic crystals, mol wt 334.79, sp gr 8.16, and has a hardness of 3 on the Mohs scale. It is very slightly soluble in water, melts at 917°C, and is prepared by melting lead and tellurium together. Lead teUuride has semiconductive and photoconductive properties. It is used in pyrometry, in heat-sensing instmments such as bolometers and infrared spectroscopes (see Infrared technology AND RAMAN SPECTROSCOPY), and in thermoelectric elements to convert heat directly to electricity (33,34,83). Lead teUuride is also used in catalysts for oxygen reduction in fuel ceUs (qv) (84), as cathodes in primary batteries with lithium anodes (85), in electrical contacts for vacuum switches (86), in lead-ion selective electrodes (87), in tunable lasers (qv) (88), and in thermistors (89). 

Similar to PbSe, the controlled growth of lead telluride, PbTe, on (111) InP was demonstrated from aqueous, acidic solutions of Pb(II) and Cd(II) nitrate salts and tellurite, at room temperature [13]. The poor epitaxy observed, due to the presence of polycrystalline material, was attributed to the existence of a large lattice mismatch between PbTe and InP (9%) compared to the PbSe/InP system (4.4%). The characterization techniques revealed the absence of planar defects in the PbTe structure, like stacking faults or microtwins, in contrast to II-VI chalcogenides like CdSe. This was related to electronic and structural anomalies. 

A similar procedure has been used to cathodically deposit lead telluride, PbTe, onto n-Si(lOO) wafers from an acidic electrolyte containing Pb(ll) and Te(IV) species at ambient conditions [106], Rock salt PbTe particles with size from 80 to 180 nm were obtained, distributed randomly on the Si substrate. The mechanism of PbTe nucleation was considered to involve OPD of 3D islands of tellurium followed by lead UPD. The barrier for anodic current formed at the n-Si/PbTe interface rendered the deposition of PbTe irreversible, although high-efficiency photooxidation... 

The electrochemical behavior of single-crystal (100) lead telluride, PbTe, has been studied in acetate buffer pH 4.9 or HCIO4 (pH 1.1) and KOH (pH 12.9) solutions by potentiodynamic techniques with an RRDE setup and compared to the properties of pure Pb and Te [203]. Preferential oxidation, reduction, growth, and dissolution processes were investigated. The composition of surface products was examined by XPS analysis. It was concluded that the use of electrochemical processes on PbTe for forming well-passivating or insulating surface layers is rather limited. 

Lasser, E., and H. Levinstein Optical properties of lead telluride. Physic. 

PbTe (c). Fabre3 found 104.5 for the heat of solution of solid lead telluride in saturated bromine water. These data yield, for PbTe (c), <2/= 19.1 or 6.0, depending upon whether tellurate or tellurite was formed. Fabre3 said that the product was tellurite, but in another experiment he found that tellurium dissolved under the same conditions to form tellurate. 

Bu ss, D. D., and N. J. Parada (1970). Calculation of the optical constants of lead telluride from augmented-plane-wave k-p energy bands. Phys. Rev. Bl, 2692-99. 

The starch-iodine method has been used for determining iodide (or iodine) in natural waters [4,5,43], milk [1], and silicate minerals [3]. The extractive method has been applied in determinations of iodine in brine [44], rocks [45], and lead telluride [46]. 

Lead Telluride. PbTe mol wt 334.82. Pb 61.89%, Te 38,11%. Found in nature as the mineral altaite. Prepd from lead nitrate, sodium carbonate and powdered tellurium Montignie, Bull Soc. Chim. France 1947, 750. Prepn of single crystals by heating stoichiometric quantities of the elements in a graphite cup or Fused quartz tube Brady,. / Elecirochem. Soc. 101, 466(1954). 

PbTe[gl LEAD TELLURIDE (GAS) 1310 Pu02 PLUTONIUM DIOXIDE 1352... 

---