Collective Magnetic Behavior of 11 nm Photo-Switchable CsCoFe Prussian Blue Analogue Nanocrystals: Effect of Dilution and Light Intensity

Abstract

The collective magnetic behavior of photoswitchable 11 nm cyanide-bridged nanoparticles based of the Prussian blue analogue CsCoFe were investigated when embedded in two different matrices with different concentrations. The effect of the intensity of light irradiation was studied in the less concentrated sample. Magnetization studies and alternating magnetic susceptibility data are consistent with a collective magnetic behavior due to interparticle dipolar magnetic interaction for the two compounds, even though the objects have a size that place them in the superparamagnetic regime.

Magnetic Hysteresis in a Monolayer of Oriented 6 nm CsNiCr Prussian Blue Analogue Nanocrystals

“…22 We have also shown, recently, that this is also the case for CsCoFe photomagnetic nanocrystals. 64 Therefore, since the nanocrystals are rather closely packed on the HOPG substrate (Figure 2), the opening of the magnetic hysteresis loop can only be due to magnetic dipolar interactions among the single-magnetic-domain nanocrystals and not to the blocking of the magnetization of isolated objects. The isolated nanocrystals that are in the single-magnetic-domain range have their surface Ni II species with their local magnetic moments lying in the plane of the surface.…”

“…However, a material containing nanocrystals with weaker separation presents a collective behavior dominated by interparticle magnetic dipolar interactions . We have also shown, recently, that this is also the case for CsCoFe photomagnetic nanocrystals . Therefore, since the nanocrystals are rather closely packed on the HOPG substrate (Figure ), the opening of the magnetic hysteresis loop can only be due to magnetic dipolar interactions among the single-magnetic-domain nanocrystals and not to the blocking of the magnetization of isolated objects.…”

Bistable Spin‐Crossover Nanoparticles for Molecular Electronics

“…The most obvious protocol to synthesize naked NPs is by "direct addition" of the precursors under a highly diluted concentration, forming small nucleation seeds to obtain small NPs, Figure 2a. [14][15][16][17] This protocol is well suited for synthesizing NPs based on non-neutral coordination polymers, ensuring colloidal stability in the resulting NPs. The primary drawback of the direct synthesis method is that it is restricted to producing small NPs (4-16 nm).…”

“…Last but not least, another possibility uses a matrix that can interact with the precursors acting as a template for the Reproduced with permission. [15] Copyright 2021, MDPI. b) Reproduced with permission.…”

Perspectives on Molecular Materials—A Tribute to Professor Peter Day

“…The contribution by T. Mallah, L. Catala et al at the University of Paris-Saclay (France), ref. [18], shows the collective magnetic behavior of photo-switchable cyanide-bridged nanoparticles, based on the Prussian blue analogue CsCoFe, when embedded in different matrices with different concentrations. The authors study the effect of the intensity of light irradiation and show that the magnetization and AC magnetic susceptibility data suggest a collective magnetic behavior due to interparticle dipolar magnetic interactions, despite the nanoparticles having a size that places them in the superparamagnetic regime.…”