Multiferroic Memories

Abstract

Multiferroism implies simultaneous presence of more than one ferroic characteristics such as coexistence of ferroelectric and magnetic ordering. This phenomenon has led to the development of various kinds of materials and conceptions of many novel applications such as development of a memory device utilizing the multifunctionality of the multiferroic materials leading to a multistate memory device with electrical writing and nondestructive magnetic reading operations. Though, interdependence of electrical- and magnetic-order parameters makes it difficult to accomplish the above and thus rendering the device to only two switchable states, recent research has shown that such problems can be circumvented by novel device designs such as formation of tunnel junction or by use of exchange bias. In this paper, we review the operational aspects of multiferroic memories as well as the materials used for these applications along with the designs that hold promise for the future memory devices.

Effects of Mn doping on structural, dielectric and multiferroic properties of BiFeO3 nanoceramics

“…High degree of freedom for the control of magnetism using electric filed and vice versa can be possible because of the magnetoelectric (ME) coupling in these materials. Recently, these materials have become the subject of intense interest for the scientific community because of their potential applications [1][2][3]. Among various single phase multiferroics, the rhombohedrally distorted perovskite structured bismuth ferrite (BiFeO 3 or BFO) with a generic formula of ABO 3 structure and R3c symmetry carries much importance due to its room temperature ferroelectric properties with high Curie temperature (T c ~ 830 o C) and weak ferromagnetic properties below the antiferromagnetic Neel's temperature (T N ~ 370 o C) [4].…”

Structural, Magnetic and Electrical Properties of Barium Titanate and Magnesium Ferrite Composites

“…This type of material has more than one ferroics ordering such as ferroelectricity and ferromagnetic ordering where the electrical polarization can be switched with magnetization switching and vice versa (Roy et al 2012). Ferroelasticity and ferrotoroidics are two other ferroics ordering that may exist in the multiferroics materials.…”

Enhancement in magnetic properties of Ba-doped BiFeO 3 ceramics by mechanical activation

“…It crystallizes in a rhombohedrally distorted perovskite structure with space group R3c and undergoes ferroelectric transition at 1103 K. It is a G-type antiferromagnet with magnetic transition at the Neel temperature of 643 K [5,6]. As both the transition temperatures are well above room temperature, it is a potential candidate for practical applications in novel magnetoelectric devices [7]. However, limitations such as formation of impurity phases due to Bi loss, presence of defects and very low magnetization due to modulated spin spiral structure with periodicity of 62 nm in addition to the G-type antiferromagnetism, restrict the use of bulk BFO in real applications [8].…”