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The Jones group in collaboration with UCL, Imperial College and the LCN investigate the effect of fluorination on the magnetic properties of phthalocyanine thin films in the Journal of Applied Physics.

A combinination of thin film growth, XRD analysis, SQUID magnetometry, and theoretical modelling have been used to evaluate the behaviour of the fully fluorinated analogue of Copper (II) Phthalocyanine.

Magnetic measurements highlight that all the films and powders are paramagnetic; the low exchange interaction is confirmed by calculations of exchange couplings using DFT and GFPT methods. In comparison, the non-fluorinated CuPc films were shown to be antiferromagnetic with J ∼ 2 K in the α-phase, and paramagnetic in the β-phase. The difference in crystal structure of F₁₆CuPc from CuPc in thin films is highlighted as a probable cause for this difference in behaviour.

Despite the large difference in electronegativity between hydrogen and fluorine, the measured magnetic properties are only weakly affected by fluorination.

Although it is paramagnetic in the current structure, F₁₆CuPc could potentially have exchange couplings that surpass those in CuPc. The distinct electronic properties compared to CuPc, in particular the shift in the one-electron spectrum, would also allow charge transport and spin coupling to be tuned independently in CuPc/F₁₆CuPc structures.