STUDY OF A MULTIFERROIC FILMS DEPOSIT ON POROUS SILICON BY ELECTRODEPOSITION METHOD

Abstract

The magnetoelectric materials known seignetomagnets are the new class of materials, in which magnetic and ferroelectric ordering coexist. Very few seignetomagnetics exist in nature or have been synthesized in the laboratory. Bismuth ferric oxide (BFO) is one of them, which is of particular interest. It exhibits a rhombohedraly distorted pervoskite structure and antiferromagnetic ordering with TN — 643 K and ferroelectric properties with a high Curie temperature of about 1103 K. The multiferroic films have applications in the field of spintronics and have the potential applications in information. Storage devices and sensors. The BiFeO3 has been interesting due to special type of structure which gave the large value of remanant polarization and weak antiferromagnetism. The poor interface between ferroelectric / si and inter diffusion of ions between the ferroelectric films and si substrate degrade the device performance of integrated circuits. In order to remove that problem many researcher have insert a insulating buffer layers between the ferroelectric films and si substrate by forming a metal-ferroelectric-insulators-semiconductors (MFIS) structure. The study of physical properties of material embedded into solid nano pores matrices attract a great attention. Besides all other porous material porous silicon is the best of them which increase the resistivity, photoluminescence and the ferroelectric with the small value of polarization and porous silicon solved the interface problem between ferroelectric and substrate. Porous silicon is constituted by a nanocrystalline skeleton (quantum sponge) immersed in a network of pores. As a result porous silicon is characterized by a very large internal surface area (500m2/em3). This internal surface is passivated but remains highly chemically reactive. The work in this report present a new undiscovered area for research on porous silicon as a substrate for multiferroic material deposition. The multiferroic films of BFO are deposited by using electrodeposition technique and spray technique, deposit on n-type porous silicon and n-type si substrate. The BFO film prepared by electrodeposition method having the large value of remanent polarization Pr is 50.12 μC/cm2 The correlation between morphology and ferroelectric behavior of such semiconducting/multiferroic system will be determined. By varying the pores size and deposition time we can tune the ferroelectric properties of multiferroic films of BiFeO3, which are studied here. The switching and fatigue kinetics of the BFO films have been studied by effect of pores size, deposition time and pulse amplitude.