Naslov
Multiferroics: from physics to application

Autori
Pajić, Damir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Innovation - Driven Defence Enterprising / - Zagreb, 2015

Skup
Innovation - Driven Defence Enterprising

Mjesto i datum
Zagreb, Hrvatska, 19.10.2015. - 20.10.2015

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
multiferroic; magnetization; polarization; sensor; memory

Sažetak
Multiferroics are materials in which two or more orders exist. For example they could be ferromagnetic and ferroelectric at the same time, or ferroelastic and ferrotoroidic, in any combination. Research of the multferroics is intensified during the last decade, with the aim to understand the physics responsible for coexistence of the two orders, which was usually considered as incompatible. Special efforts are devoted to explain the origin of very complex and exotic interactions which induce large coupling between the two ferroic states. Besides those fundamental questions in condensed matter physics, the research is motivated also with the possibility of application of multiferroics. Magneto-electric coupling of two ordered states can be used for novel memory elements, spintronic devices, sensors and actuators, and other still developing concepts. BiFeO3 is the most known room-temperature multiferroic, which is ferroelectric below temperature of 1100K and antiferromagnetic below 640K. However, the coupling between the two orders is very weak and researchers are still trying to design similar compounds which could exhibit more prospective coupling and relatively high polarization and magnetization. From the other side there are materials with stronger magneto-electric coupling, but often the value of polarization is very small, or the effect appears at low temperatures only (temperatures of liquid helium). One important strategy in design of the materials was to substitute some atoms within the known structures in order to induce additional interactions, but this often produced counter-effects, like in Fe doped BaTiO3 which did not become intrinsic multiferroic and even was loosing the polarization. Besides the inorganic materials, new directions of multiferroics research have big expectations in field of the organic and hybrid inorganic-organic materials, among which the metal-organic frameworks seem to be very perspective. Many cumbers are met during the design and research of multiferroics, especially when the effect is desired to appear at room temperature. While many materials show the indirect signs of the magneto-electric coupling, the direct experimental evidences are often missing, since the commercial instrumentation for investigation is not available, and home-made experimental set-up should be constructed. Search for multiferroic materials is also restricted because of the not so straight-forward chemical syntheses which should be invented. At the end, full understanding of the phenomena requires advanced theoretical approaches. Therefore, the multidisciplinary collaboration is needed for a fruitful research. Besides the scientific outcomes, the whole process results with the new equipment, novel methods of chemical syntheses and more wide development in those related fields, including also the applicative branches.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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