Ultra-high Seebeck coefficient of a thermal sensor through entropic optimisation of ligand length of Fe(ii) spin-crossover (SCO) materials
Document Type
Article
Publication Date
6-23-2021
Abstract
In this work, we present a spin-crossover (SCO) complex molecular formulation Fe(L-n)(2)](BF4)(2) in an electrochemical single couple solution. A Seebeck voltage arises when an electrochemical single couple solution is subjected to a temperature difference, resulting in a single couple reaction at either terminal of the electrochemical cell. The ultrahigh Seebeck coefficients were obtained due to a number of molecular optimisation strategies. The Fe(L-16)(2)](BF4)(2) complex demonstrated a maximum Seebeck coefficient of 8.67 mV K-1, achieved through a six-pronged approach to maximise entropy during the transition from low spin (LS) to high spin (HS) through: (i) a change in spin state, (ii) a change in physical liquid crystalline state, (iii) the spin Seebeck effect, (iv) the kosmotropic and chaotropic effect, (v) the fastener effect and (vi) thermal heat absorbance. A reduction of the Seebeck coefficient to 1.68 mV K-1 during the HS-LS transition at higher temperatures is related to the single spin state transition entropy change. In summary, this paper presents a systematic study to identify the contributing factors in the production of a sensor with an ultrahigh Seebeck coefficient for energy harvesting through the optimisation of its molecular entropy elements.
Keywords
Ultra-high Seebeck, Thermal sensor, Entropic optimisation, Ligand length, Fe(ii) spin-crossover (SCO) materials
Divisions
sch_ecs,CHEMISTRY,PHYSICS
Funders
Universiti Malaya (FG009-17AFR),Universiti Malaya (GPF022A-2018),Universiti Malaya (IIRG002A-1911SS),Universiti Malaya (IF009-2020)
Publication Title
RSC Advances
Volume
11
Issue
34
Publisher
Royal Society of Chemistry
Publisher Location
THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND