Elastic stiffness coefficients of thenardite and their pressure and temperature dependence
MetadataShow full item record
Copyright © 2012 Oldenbourg Wissenschaftsverlag
The elastic stiffness coefficients, cij , of orthorhombic Na2SO4 thenardite (space group Fddd) were measured with an ultrasonic plane wave technique at ambient temperature as a function of hydrostatic pressure in the range of 0.1 – 70 MPa. The variation of the cij in the range of 1 – 5000 MPa was studied with density functional theory (DFT) based calculations. The experimental results and the DFT calculations were used to derive a force-field model, which was then employed to compute lattice parameters and elastic stiffness tensors of thenardite and of two other Na2SO4 polymorphs as functions of the temperature based on quasi-harmonic lattice dynamics. The structural parameters of the three polymorphs measured at high temperatures are reproduced to within 1.7% by the present calculations. Phases II (space group Pbnm) and III (Cmcm) appear to have significantly higher entropies than thenardite in agreement with their metastable formation at higher temperatures.
Showing items related by title, author, creator and subject.
Acute heat illness in underground miners : the clinical state, haematology, biochemistry and risk factors.Donoghue, Alan M. (2000)Objectives - To examine the incidence, clinical state, personal risk factors, haematology and biochemistry of heat exhaustion cases occurring at a deep underground metalliferous mine. To describe the underground and surface ...
An investigation of the physiological and biochemical responses elicited by Panulirus cygnus to harvesting, holding and live transport.Spanoghe, Patrick T. (1996)The western rock lobster (WRL), Panulirus cygnus is a decapod crustacean which is found in abundance in the coastal waters of Western Australia and which supports a major fishery of economic importance for the State, with ...
Logie, K.; Kusel, M.; Sly, P.; Hall, Graham (2011)Background: Exhaled breath temperature (EBT) has been proposed for the non-invasive assessment of airway inflammation. Previous studies have not examined the influence of room temperature or lung size on the EBT. Objective: ...