Magnetic surfactants as molecular based-magnets with spin glass-like properties

Abstract

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms Magnetic Surfactants as Molecular Based-Magnets with Spin Glass-Like Properties AbstractThis paper reports the use of muon spin relaxation spectroscopy to study how the aggregation behavior of magnetic surfactants containing lanthanide counterions may be exploited to create spin glass-like materials.Surfactants provide a unique approach to building in randomness, frustration and competing interactions into magnetic materials without requiring a lattice of ordered magnetic species or intervening ligands and elements. We demonstrate that this magnetic behavior may also be manipulated via formation of micelles rather than simple dilution, as well as via design of surfactant molecular architecture. This somewhat unexpected result indicates the potential of using novel magnetic surfactants for the generation and tuning of molecular magnets.

Magnetic and Phase Behavior of Magnetic Water‐in‐Oil Microemulsions

“…This paper demonstrates how magnetic microemulsions can be formed from a combination of surfactants, which allows for easy control of microemulsion size and shape. This should be useful for the future study of nanomagnet design [15]. We demonstrated that although bulk microemulsions can be manipulated in a magnetic field [12] individual droplets could not according to SANS.…”

“…This should be useful for the future study of nanomagnet design [15]. We demonstrate that although bulk microemulsions can be manipulated in a magnetic field [12] individual droplets could not according to SANS.…”

“…The phase behavior and stability of the mixed surfactant magnetic microemulsions has been characterized and droplet movement in a magnetic field has been investigated using smallangle neutron scattering (SANS). The study demonstrates how magnetic surfactants can replace conventional surfactants in formulations and may help those interested in designing novel tunable nanomagnets [12] and spin-glass systems [15]. Finally, using SANS in a strong magnetic field, it was clear that manipulation of the droplets was not possible.…”

EMuS Muon Facility and Its Application in the Study of Magnetism

“…With µSR results, there are three possible lines of evidence for the existence of a spin liquid: (1) the ZF signals change continuously without showing spin precession at all temperatures even down to the mK range; (2) ZF-µSR shows a relaxation plateau feature at low temperature from a weak slowing down of the spin fluctuation, rather than the continuously increasing in a spin glass system; (3) the stretching exponent, β, gradually drops to a small value from high temperature to the base temperature. i.e., for QSL materials β is always above 1/2, but for a spin glass system, β is expected to drop to 1/3 at the spin freezing temperature [23,24]. Figure 10 shows YbMgGaO 4 that supports the formation of a gapless U(1) QSL ground state in this triangular antiferromagnet [25].…”

Generating randomness: making the most out of disordering a false order into a real one

“…This method generated high-performance electrochromic structures. Surfactants provide an approach to building in randomness in generated magnetic behavior that can be manipulated via the formation of micelles and the design of a surfactant molecular architecture [91].…”