Meet the editor

Dr. Dipti Ranjan Sahu is an Associate Professor of Physics in the Department of Natural and Applied Sciences at the Namibia University of Science and Technology (NUST). He received his doctoral degree in Physics from the Institute of Materials Science, Utkal University, India. After earning his Ph.D., he worked as a postdoctoral researcher and visiting scientist and served as a faculty member in several institutions such as the National

Taiwan University, National Cheng Kung University (Taiwan), and the University of Witwatersrand (South Africa). His research focus is on multifunctional materials including nanomaterials, ceramics, composites, spintronics, magnetic materials, and the application of functional materials in devices. He has published more than 100 peer-reviewed articles, 2 books, 2 book chapters, and more than 100 research articles in conference proceedings and meetings.

Contents

*and Omar Fassi-Fehri*

*by Rajesh Kumar Rajagopal*

Magnetized Multilayers

**Preface XI**

**Chapter 1 1**

**Chapter 2 33**

**Chapter 3 49**

**Chapter 4 67**

**Chapter 5 93**

**Chapter 6 115**

Stabilizing Zero-Field Skyrmions at Room-Temperature in Perpendicularly

*by Jeovani Brandão, Marcos Vinicius Puydinger dos Santos and Fanny Béron*

Modeling the Bulk and Nanometric Dielectric Functions of Au and Ag *by Brahim Ait Hammou, Abdelhamid El Kaaouachi, Abdellatif El Oujdi,* 

Effect of M Substitution on Structural, Magnetic and Magnetocaloric Properties of R2Fe17-x Mx (R = Gd, Nd; M = Co, Cu) Solid Solutions

*Adil Echchelh, Said Dlimi, Chi-Te Liang and Jamal Hemine*

Magnetic Properties of Heusler Alloys and Nanoferrites

*by Devinder Singh and Kuldeep Chand Verma*

*by Mosbah Jemmali and Lotfi Bessais*

Magnetic Skyrmions: Theory and Applications

*by Lalla Btissam Drissi, El Hassan Saidi, Mosto Bousmina* 

Skyrmions in Thin Films, Interfaces and Antiferromagnetism

## Contents


Preface

This book contains six chapters with some of the most exciting theoretical concepts and reviews the development of magnetic skyrmions and their application in magnetic materials. The first three chapters discuss magnetic skyrmions in solids, thin films, and multilayers. The fourth chapter focuses on the modeling of bulk and nanometric dielectric, and the final two chapters deal with specific intermetallic compounds and Heusler alloys. These chapters explain the fundamentals and present

The topics presented here will be very helpful to students, researchers, academicians, and professionals. This book can also be used as a text for those who wish to engage

I would like to thank the authors who contributed their interesting and informative chapter for this book. Finally, I am pleased to thank all the members of the publishing house who have helped us with editing, revising, and reviewing this book and so

**Dipti Ranjan Sahu**

Windhoek, Namibia

Department of Natural and Applied Sciences, Namibia University of Science and Technology,

current research trends on magnetic skyrmions for technological innovation.

in the physics of skyrmions in magnetic systems and related materials.

much more.

Skyrmions are generally known as nanoscale magnetic vortices, a type of quasiparticles that are driven by ultra-low electrical current. This skyrmion is a point-like region of reversed magnetization in a uniform magnet. The magnetic skyrmions found in magnetic materials exhibit spiral magnetism. Magnetic skyrmions are anticipated to allow for the existence of discrete magnetic states, which are significantly more energetically stable than their single-domain counterparts. Magnetic skyrmions have important applications in microwave communication, logic computing technology, and memory and logic devices in terms of storing information. Magnetic skyrmions within a film or nanotrack can be manipulated using spin currents or spin waves that can have more applications in data storage and spintronic devices and show outstanding magnetic and transport properties. Magnetic skyrmionics is an advanced and active research field that reveals fundamental physics, encourages the development of next-generation high-density efficient information devices, creates and manipulates nanometer-size skyrmions in devices, and develops compatible materials at room temperature by all-electrical means. There are still several challenges such as the interaction of skyrmions with other magnetic textures, the particle-wave duality of skyrmions, skyrmion lattice phase transitions, and the use of skyrmion lattices as magnonic crystals that are needed to address for designing fully functional and competitive skyrmion devices. This book addresses scientific advances and reveals an interesting fact that skyrmions can create and access magnetic skyrmions under ambient room-temperature conditions for next-generation devices.
