ORCID Profile
0000-0002-2348-6993
Current Organisation
University of Cambridge
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Publisher: Springer Science and Business Media LLC
Date: 12-10-2020
Publisher: Springer Science and Business Media LLC
Date: 05-06-2020
DOI: 10.1038/S41467-020-16727-2
Abstract: Magnetoelectric coupling at room temperature in multiferroic materials, such as BiFeO 3 , is one of the leading candidates to develop low-power spintronics and emerging memory technologies. Although extensive research activity has been devoted recently to exploring the physical properties, especially focusing on ferroelectricity and antiferromagnetism in chemically modified BiFeO 3 , a concrete understanding of the magnetoelectric coupling is yet to be fulfilled. We have discovered that La substitutions at the Bi-site lead to a progressive increase in the degeneracy of the potential energy landscape of the BiFeO 3 system exemplified by a rotation of the polar axis away from the 〈111〉 pc towards the 〈112〉 pc discretion. This is accompanied by corresponding rotation of the antiferromagnetic axis as well, thus maintaining the right-handed vectorial relationship between ferroelectric polarization, antiferromagnetic vector and the Dzyaloshinskii-Moriya vector. As a consequence, La-BiFeO 3 films exhibit a magnetoelectric coupling that is distinctly different from the undoped BiFeO 3 films.
Publisher: Springer Science and Business Media LLC
Date: 24-02-2021
Publisher: Springer Science and Business Media LLC
Date: 12-05-2021
DOI: 10.1038/S41467-021-22793-X
Abstract: Magnetostrictive materials transduce magnetic and mechanical energies and when combined with piezoelectric elements, evoke magnetoelectric transduction for high-sensitivity magnetic field sensors and energy-efficient beyond-CMOS technologies. The dearth of ductile, rare-earth-free materials with high magnetostrictive coefficients motivates the discovery of superior materials. Fe 1− x Ga x alloys are amongst the highest performing rare-earth-free magnetostrictive materials however, magnetostriction becomes sharply suppressed beyond x = 19% due to the formation of a parasitic ordered intermetallic phase. Here, we harness epitaxy to extend the stability of the BCC Fe 1− x Ga x alloy to gallium compositions as high as x = 30% and in so doing dramatically boost the magnetostriction by as much as 10x relative to the bulk and 2x larger than canonical rare-earth based magnetostrictors. A Fe 1− x Ga x − [Pb(Mg 1/3 Nb 2/3 )O 3 ] 0.7 −[PbTiO 3 ] 0.3 (PMN-PT) composite magnetoelectric shows robust 90° electrical switching of magnetic anisotropy and a converse magnetoelectric coefficient of 2.0 × 10 −5 s m −1 . When optimally scaled, this high coefficient implies stable switching at ~80 aJ per bit.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-02-2022
Abstract: Antiferroelectric materials have seen a resurgence of interest because of proposed applications in a number of energy-efficient technologies. Unfortunately, relatively few families of antiferroelectric materials have been identified, precluding many proposed applications. Here, we propose a design strategy for the construction of antiferroelectric materials using interfacial electrostatic engineering. We begin with a ferroelectric material with one of the highest known bulk polarizations, BiFeO 3 . By confining thin layers of BiFeO 3 in a dielectric matrix, we show that a metastable antiferroelectric structure can be induced. Application of an electric field reversibly switches between this new phase and a ferroelectric state. The use of electrostatic confinement provides an untapped pathway for the design of engineered antiferroelectric materials with large and potentially coupled responses.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Bhagwati Prasad.