The sublimation of metals at low pressures

Abstract

Many metals have been found to exhibit evidences of volatility at temperatures considerably below their melting points. As long ago as 1872, Merget demonstrated that frozen mercury volatilised perceptibly in air in course of time. Demarçay, in 1882, conducted similar experiments in vacuo and found that cadmium evaporated sensibly at as low a temperature as 160°, zinc at 184°, and lead and tin at 360° C. In 1887, Zenghelio obtained evidence of the volatility of lead, copper, zinc, etc., even at room temperatures. Spring, in 1894, working at atmospheric pressure, showed that zinc was appreciably volatile at 300°, and cadmium and copper'at 500°. Roberts-Austen and Merrett, in some unpublished experiments at the Royal Mint, in 1896, detected the volatility of cadmium and zinc at 100° in vacuo , while Krafft in 1903 and 1905 investigated in some detail the volatilisation of a number of metals at low pressures. Rosenhain, at the National Physical Laboratory, has obtained beautiful crystals of sublimed zinc by heating a piece of zinc to 300° C. for some weeks in a glass tube containing hydrogen at atmospheric pressure. The notable phenomena of the interdiffusion of metals, with which Roberts-Austen’s name is associated, provide, of course, additional evidence of the vapour pressure that solid metals exert even at ordinary temperatures.

A Simple Step toward Enhancing Hydrothermal Stability of ZIF-8

“…Several of the literature has provided evidence of the vapor pressure that solid metals including Zn evaporate under low pressures even at low temperatures. 54 With a further increase in the thermal treatment temperature, the C/Zn ratio decreased due to the dominant ligand decomposition. The outermost surface composition ratio of N/C increased after a minimum decline for ZIF/450.…”

“…Although the thermal treatment temperature of 450 °C is much lower than the boiling point of Zn (907 °C), it is believed that the disappearance of Zn in the outermost surface of ZIF-8 can be easily caused by the breaking of Zn–N. Several of the literature has provided evidence of the vapor pressure that solid metals including Zn evaporate under low pressures even at low temperatures . With a further increase in the thermal treatment temperature, the C/Zn ratio decreased due to the dominant ligand decomposition.…”

A Review of Terminology Used to Describe Soot Formation and Evolution under Combustion and Pyrolytic Conditions

“…Deposition is the thermodynamic phase transition of a gas directly into a solid and is the reverse of sublimation. − , Deposition can proceed by formation of electrostatic, covalent, or metallic bonds, depending on the material. When the uptake of material onto a solid surface is not the result of a thermodynamic phase transition, “adsorption” should be used to describe the process.…”

“…Sublimation is the thermodynamic phase transition of a solid directly into a gas and is the reverse of deposition; − , see the Deposition section.…”

Kinetic Model for the Sublimation of a Solid and Evaporation of Colloidal Particles from a Solid Substrate

“…Sublimation is a rather rare solid-to-vapor-phase transition occurring at temperatures and pressures below the triple point. Some materials (such as zinc and cadmium) sublimate at low pressures and thus may cause problems in high-vacuum applications. − Carbon dioxide is a common example of a chemical compound that sublimates at atmospheric pressure: a block of solid CO 2 (dry ice) at room temperature and at 1 atm (pressure) will turn into gas without first becoming a liquid …”