Physics
To exploit and control magnetism, technology often relies on electromagnets, which limit hardware configurations due to their size and energy consumption. As an alternative, scientists are beginning to develop hybrid nanomaterials. Responsive to both electric and magnetic fields, these constructs offer valuable performance economies, and provide the means to realise new applications in various sectors.
Developing hybrid multiferroic materials for data storage and wireless applications
Coupled ferroelectric and ferromagnetic domains in a hybrid multiferroic material
microwave components. Power savings are one incentive, but another exciting factor is the multi-functionality that hybrids offer. The potential they hold could lead to the evolution of entirely new forms of information storage. Specialising in experimental studies of
magnetic phenomena in new materials and nanoscale structures, van Dijken’s team’s approach to creating multiferroic hybrids eschews the synthesis of new single-phase materials. Instead, its method has been to combine, and functionally interlink existing materials properties.
that possess “We’re the investigating
required new
methods that enable electric field controlled magnetism,” says van Dijken. “This will allow us to control the magnetic properties of our material, which, in this instance, is a thin, film-like nano-scale structure. Because magnetic properties are conventionally modulated by magnetic fields, the concept is principally unorthodox.” To engineer these hybrid structures, the
researchers use one stable ferroelectric material and one stable ferromagnetic material, both of which demonstrate the requisite behaviours when exposed to high temperatures. Built at the nanoscale, thin films of each material are linked together by strong coupling at their interfaces, enabling them to be used as a single entity (although the ferroelectric and ferromagnetic properties of the compound remain physically separated). If the connection between the materials can be sustained, magnetic fields will not only influence the ferromagnetic film, but also
its
“Some materials exhibit spontaneous electric or magnetic order. These materials are called ferroelectric and ferromagnetic, respectively,”
explains Professor
Sebastiaan van Dijken, leader of the Nanomagnetism and Spintronics Group at Aalto University. “However, among these two ferroic materials there is little overlap. While it is possible to create materials that achieve this overlap in a laboratory setting, it is usually at very
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low temperatures and so is fairly useless in terms of the development of components for nanoelectronic devices.” Creating materials that can be influenced
by both magnetic and electric forces – so called “multiferroics” – is central to van Dijken’s current research. This emerging field is currently being addressed mainly by academics, although there is notable attention from companies with interests in data storage, magnetic sensors and
ferroelectric counterpart.
Conversely, if a bias voltage is applied across these junctures, the properties of the magnetic segment of the structure can be manipulated using an electric field. Choosing appropriate materials, engineering
robust interfaces and
optimising strong interferroic coupling are all essential in ensuring the effectiveness of the entire structure. The Nanomagnetism and Spintronics Group has total control over their entire
Insight Publishers | Projects
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