Thermodynamic assessment of the Ni–Te system

Abstract

A thermodynamic assessment of the Ni-Te system has been performed using the Calphad method, based on experimental data available in the literature. The proposed description has been developed for use in the modeling of fissionproduct-induced internal corrosion of stainless steel cladding in Generation IV nuclear reactors. DFT calculations were performed to obtain 0 K properties of solid phases to assist the thermodynamic optimization. The ionic liquid twosublattice model was used, and most solution phases were modeled using interstitial metal sub-lattices. With a strict number of parameters, the resulting description satisfactorily reproduces all thermodynamic properties and hightemperature phase transitions. The metastable miscibility gap in the Ni-rich liquid that is experimentally suggested is not present in the final description. The d phase exhibits a metastable order-disorder transition between the CdI 2 and NiAs types of interstitial nickel distribution. The CdI 2 prototype is the stable space group at room temperature. Low-temperature ordering phase transitions have been disregarded in this description, since they are not of interest to the application of corrosion in nuclear reactors.

Experimental Phase Diagram Study of the Fe-Ni-Te System

“…In addition, Data of 61 at.% Te from Terzieff. [8] Binary data from Arvhult et al [19,20] [19,20] DTA studies present the liquidus and solidus temperatures for isoplethal sections of 44-80 at.% Te, complementing the work by Terzieff, [8] which only considered 61 at.% Te. Metallographic studies show that the b2 phase forms Widmanstätten structures, precipitated inside the ternary s phase regions, which supports theories that the s phase extends at higher temperature to reach above the b2 phase towards the Fe-Te binary high-temperature rhombohedral phase, [2] also known as b 0 .…”

Rectangular-Phase Tellurene on Ni(111) from Monolayer Films to Periodic Striped Patterns

“…High-purity Te was evaporated from a Knudsen cell at ∼210 °C onto the substrates kept at RT. The low growth temperature of RT can avoid the formation of Ni–Te surface alloys due to the extremely low solubility of Te in bulk Ni at RT, i.e., almost no solubility reported previously based on the lattice parameter measurements. , Specific annealing processes were performed for the different samples to form compact 2D Te structures on metal substrates and to evaluate their thermal stabilities. The deposition time/amount of Te on metal substrates was varied for achieving different structures of Te from monolayer films to thick striped patterns on Ni(111).…”

Controlling Phase in Colloidal Synthesis

“…Compared to the metal chalcogenides, the phase control of metal pnictides in colloidal synthesis is far less studied even though they are important catalysts in oxygen reduction reactions and hydrogen evolution reactions. − Pnictides have a comparable number of phases to the chalcogenides; for example, there are ten nickel sulfides, seven nickel selenides, and nine nickel tellurides, while there are four nickel nitrides, ten nickel phosphides, and five nickel arsenides. , The lack of studies does not come from an absence of phases, but rather from synthetic challenges such as potentially dangerous reagents and extreme heat (700+ °C). , Many metal pnictides are important catalyst materials, , therefore, there is a large opportunity for growth in the area of phase control of the metal pnictides.…”