Magnetoelectric, Raman, and XPS Properties of Pb 0.7 Sr 0.3 [(Fe 2/3 Ce 1/3 ) 0.012 Ti 0.988 ]O 3 and Pb 0.7 Sr 0.3 [(Fe
- PDF / 679,026 Bytes
- 6 Pages / 593.972 x 792 pts Page_size
- 82 Downloads / 194 Views
MAGNETOELECTRIC (ME) effects, which are defined as magnetic-field-induced polarization direct magnetoelectric and electric-field-induced magnetization converse magnetoelectric, have been extensively investigated in various single-phase multiferroics such as BiFeO3,[1] TbMn2O5,[2] BaTiO3-CoFe2O4,[3] 0.62Pb(Mg1/3Nb2/3) O3-0.38PbTiO3,[4] Pb0.7Sr0.3[(Fe2/3Ce/La1/3)0.012Ti0.988]O3,[5] etc. In these single-phase multiferroics such as BiFeO3[1] and TbMn2O5,[2] the intrinsic coupling between polarization and magnetization at atomic scale is generally weak or remains far less than room temperature, which hinders their practical applications. However, orders of magnitude of large ME coefficients (aE) have been achieved in some perovskites, BaTiO3- and PbTiO3[3–8]-based multiferroics owing to the room temperature large value of aE and coexistence of ferromagnetism and ferroelectricity. The aE quantifies the strength of ME coupling defined by direct ME effect or by its converse ME effect. Therefore, these perovskites bring an alternative route in realizing many practical multifunctional applications and become one of the important portions in ME multiferroic materials. Because interactions between the magnetic and the electric orders of multiferroics lead them to additional functionalities for ME memory devices, waveguides, transducers, sensors, energy harvesters, and spintronic-based devices. ME coupling in a material can be either extrinsic (obtained by applying external fields) or intrinsic KULDEEP CHAND VERMA, Associate Professor, and MANOJ KUMAR, M.Sc. Student, are with the Akal School of Physics, Eternal University, Baru Sahib, Sirmour 173101 HP, India. Contact e-mail: [email protected]; [email protected] R.K. KOTNALA, Chief Scientist, is with the National Physical Laboratory, New Delhi 110012, India. Manuscript submitted May 17, 2013. Article published online October 18, 2013 METALLURGICAL AND MATERIALS TRANSACTIONS A
(characteristic of the material).[1,2] The extrinsic coupling can be determined from the induced voltage under the action of an external magnetic field and/or induction of magnetization by applying an external electric field.[9] This coupling is being mainly investigated in perovskitebased multiferroics, which can present higher value of effective extrinsic ME coupling.[9] The strength of ME interaction is measured in terms of aE under a static magnetic field Hdc, superimposed with a small ac magnetic field Hac. The ME voltage coefficient is given by aE ¼ Vout =Hac t, where t is the sample thickness, and Vout is the induced ME voltage. On the other hand, in these single-phase multiferroic, spontaneous ME effects manifest themselves near the phase-transition temperatures, where the multiferroic state is established and an indirect interaction occurs between electric and magnetic subsystems through the elastic subsystem.[10] Recently, we have reported that Ce- and La-substituted Pb0.7Sr0.3(Fe0.012Ti0.988)O3 (PSFT) nanoparticles[5,11] result in the improvement of the coexistence of ferromagnetism and ferroelectr
Data Loading...
