Section 3

The Cobalt Oxide Based Composite Nanoparticles and Their Engineering and Medical Applications

*Cobalt Compounds and Applications*

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jeurceramsoc.2004.09.029

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2012.08.101

Chapter 3

Abstract

and Antonio C.M. Sousa

The Cobalt Oxide-Based

Composite Nanomaterial

Synthesis and Its Biomedical

and Engineering Applications

and characterization and applications of cobalt oxide-based composite

Keywords: cobalt oxide, nanocomposite, thermal properties,

materials is also included in this book chapter.

electrical properties and toxicity

1. Introduction

31

nanoparticles. The detailed analysis related to toxicity of these nanocomposite

Magnetic nanoparticles (NPs) are attracting increased researchers' interest due to their potential wide use in many engineering and medical applications. The most commonly used magnetic materials are Fe2O3, Fe3O4, Ni, Co, CoO, and Co3O4. However, among all these magnetic materials, cobalt oxide (Co3O4) nanoparticles are being preferred due to their good magnetic properties. Pure cobalt is not stable at room temperature as it can be converted to oxides like CoO, Co2O3, and Co3O4; Co3O4 is the most stable phase. It is a P-type semiconductor, and it has high Young's modulus, which varies between 116 and 160 GPa. Co3O4 exhibits a normal spinel crystal structure with occupation of tetrahedral sites by Co2+ and octahedral sites by Co3+. Its magnetic moment arises due to Co2+ ions largely because of spins, with a small contribution from spin-orbit coupling. Co3O4 has excellent properties such as gas-sensing, catalytic, and electrochemical properties, and it has been studied

Lingala Syam Sundar, Manoj K. Singh, António M.B. Pereira

The magnetic nanoparticles (NPs) are offering a wide range of applications in medical and engineering fields. Among all the magnetic nanoparticles, cobalt oxide (Co3O4) nanoparticles and its composite-based nanoparticles are attracting more interest from researchers because of its unique mechanical, thermal, and magnetic properties. The aim of this book is to bring together a number of recent contributions regarding the cobalt oxide-based composite nanoparticles from several researchers all over the world. The latest research results, innovations, and methodologies are reported in the book in order to support the discussion and to circulate ideas and knowledge about the applications of these materials in medical and engineering applications. This chapter presents the methodology for the synthesis

## Chapter 3
