Spin Transition in Arrays of Gold Nanoparticles and Spin Crossover Molecules
Artikel i vetenskaplig tidskrift, 2015

We investigate if the functionality of spin crossover molecules is preserved when they are assembled into an interfacial device structure. Specifically, we prepare and investigate gold nanoparticle arrays, into which room-temperature spin crossover molecules are introduced, more precisely, [Fe(AcS-BPP)(2)](ClO4)(2), where AcS-BPP = (S)-(4-{[2,6-(dipyrazol-1-yl)pyrid-4-yl]ethynyl}phenyl)ethanethioate (in short, Fe(S-BPP)(2)). We combine three complementary experiments to characterize the molecule-nanoparticle structure in detail. Temperature-dependent Raman measurements provide direct evidence for a (partial) spin transition in the Fe(S-BPP)(2)-based arrays. This transition is qualitatively confirmed by magnetization measurements. Finally, charge transport measurements on the Fe(S-BPP)(2)-gold nanoparticle devices reveal a minimum in device resistance versus temperature, R(T), curves around 260-290 K. This is in contrast to similar networks containing passive molecules only that show monotonically decreasing R(T) characteristics. Backed by density functional theory calculations on single molecular conductance values for both spin states, we propose to relate the resistance minimum in R(T) to a spin transition under the hypothesis that (1) the molecular resistance of the high spin state is larger than that of the low spin state and (2) transport in the array is governed by a percolation model.


molecular charge transport devices

gold nanoparticles

spin crossover molecules


E. J. Devid

Leiden University

P. N. Martinho

Universidade de Lisboa

Karlsruhe Institute of Technology, Campus North

Venkata Kamalakar Mutta

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

I. Salitros

Slovak University of Technology in Bratislava

Karlsruhe Institute of Technology, Campus North

U. Prendergast

Dublin City University

J. F. Dayen

Universite de Strasbourg

V. Meded

Karlsruhe Institute of Technology, Campus North

T. Lemma

Dublin City University

R. Gonzalez-Prieto

Universidad Autonoma de Madrid

Karlsruhe Institute of Technology, Campus North

F. Evers

Karlsruhe Institute of Technology, Campus North

Karlsruhe Institute of Technology, Campus South

T. E. Keyes

Dublin City University

M. Ruben

Karlsruhe Institute of Technology, Campus North

Universite de Strasbourg

B. Doudin

Universite de Strasbourg

S. J. van der Molen

Leiden University

ACS Nano

1936-0851 (ISSN) 1936-086X (eISSN)

Vol. 9 4496-4507