Developments in data storage : materials perspective / [edited by] S.N. ... more than 50 years old, the storage density of the hard disk drives has been increasing ...
DEVELOPMENTS IN DATA STORAGE
IEEE Press 445 Hoes Lane Piscataway, NJ 08854
IEEE Press Editorial Board Lajos Hanzo, Editor in Chief
R. Abhari J. Anderson G. W. Arnold F. Canavero
M. El-Hawary B-M. Haemmerli M. Lanzerotti D. Jacobson
O. P. Malik S. Nahavandi T. Samad G. Zobrist
Kenneth Moore, Director of IEEE Book and Information Services (BIS)
DEVELOPMENTS IN DATA STORAGE Materials Perspective Edited by S. N. Piramanayagam Tow C. Chong Data Storage Institute Agency for Science, Technology and Research (A*STAR) Singapore
IEEE Magnetics Society, Sponsor
IEEE PRESS
A JOHN WILEY & SONS, INC., PUBLICATION
Copyright © 2012 by Institute of Electrical and Electronics Engineers. All rights reserved. Published by John Wiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions. Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com. Library of Congress Cataloging-in-Publication Data: Developments in data storage : materials perspective / [edited by] S.N. Piramanayagam, Tow C. Chong. p. cm. ISBN 978-0-470-50100-9 (hardback) 1. Computer storage devices. I. Piramanayagam, S. N. II. Chong, Tow C. TK7895.M4D497 2011 621.39'7–dc22 2011006739 oBook ISBN: 978-1-118-09683-3 ePDF ISBN: 978-1-118-09681-9 ePub ISBN: 978-1-118-09682-6 Printed in the United States of America. 10 9 8 7 6 5 4 3 2 1
To my mentors Prof. Shiva Prasad, Prof. S. N. Shringi, Prof. Mitsunori Matsumoto and The Late Ms. Terue Kamoi who made a positive difference in my life S. N. Piramanayagam
To my family and all the staff of Data Storage Institute, Singapore Tow C. Chong
CONTENTS
Preface
ix
Acknowledgments
xi
Contributors
xiii
1
INTRODUCTION S. N. Piramanayagam
2
FUNDAMENTALS OF MAGNETISM Shiva Prasad and S. N. Piramanayagam
10
3
LONGITUDINAL RECORDING MEDIA S. N. Piramanayagam
33
4
PERPENDICULAR RECORDING MEDIA Kumar Srinivasan and S. N. Piramanayagam
52
5
WRITE HEADS: FUNDAMENTALS Naoki Honda and Kiyoshi Yamakawa
78
6
MAGNETORESISTIVE READ HEADS: FUNDAMENTALS AND FUNCTIONALITY Rachid Sbiaa
7
READ SENSORS FOR GREATER THAN 1 Tb/in.2 Guchang Han, Viloane Ko, Zaibing Guo, and Hao Meng
8
THIN-FILM MEDIA LUBRICANTS: STRUCTURE, CHARACTERIZATION, AND PERFORMANCE Bruno Marchon
9 10
1
97 127
144
OVERCOAT MATERIALS FOR MAGNETIC RECORDING MEDIA Allen Poh Wei Choong, S. N. Piramanayagam, and Thomas Y. F. Liew
167
HEAT-ASSISTED MAGNETIC RECORDING Ganping Ju, William Challener, Yingguo Peng, Mike Seigler, and Ed Gage
193
vii
viii
CONTENTS
11
L10 FePt FOR MAGNETIC RECORDING MEDIA APPLICATION Jiangfeng Hu, Jingsheng Chen, and Ganping Ju
12
PATTERNED MAGNETIC RECORDING MEDIA: PROGRESS AND PROSPECTS Thomas Thomson and Bruce D. Terris
223
256
13
PHASE CHANGE RANDOM ACCESS MEMORY Luping Shi, Rong Zhao, and Tow C. Chong
277
14
NONVOLATILE SOLID-STATE MAGNETIC MEMORY Randall Law Yaozhang and Sunny Y. H. Lua
297
Index
326
PREFACE
It gives us great pleasure to present this book on the developments in data storage, from a materials perspective. This book has been designed to help the final year undergraduate and graduate students of physics, materials science, chemistry, electrical engineering, and other disciplines with an interest in the magnetic recording or other emerging alternative storage technologies. This book will also help new engineers as well as professionals in the recording industry to broaden their knowledge and serve as a useful reference. It has been quite some time since a book on data storage was released and since then there have been several developments. The hard disk industry has moved from longitudinal recording technology to perpendicular recording. Even though the hard disk technology is more than 50 years old, the storage density of the hard disk drives has been increasing at a rate of about 30% per year. As of 2010, all the hard disk products are based on perpendicular recording technology. It is believed that some alternatives, such as heat-assisted magnetic recording or patterned media technology, are needed to maintain the growth of storage density which will enable the hard disk industry to maintain its superiority over competing technologies. Such growth has been (and will continue to be) brought on by various technological developments. We thought there was a need to condense these developments into a book that will benefit the readers for the next several years. With this aim, we requested several researchers from different backgrounds to write on the developments in their respective field. However, the book would not be complete if it did not provide the background information for a novice. With that in mind, we have also included some chapters that introduce the fundamentals. Chapters 1–3 provide the fundamentals and Chapters 4–9 provide the recent developments in several areas of hard disk drives. Chapters 10–12 cover the emerging technologies of hard disk drives. Even though hard disk drives have enjoyed a successful advantage over the competing technologies in terms of cheaper costs and higher capacities, their superiority is threatened by the flash memory. Since there are several books on flash memory, we did not attempt to cover it here. However, flash memory will face its hurdles in the near future and several alternative memory technologies such as phase change random access memory (PCRAM) and magnetic random access memory (MRAM) are emerging as alternatives. Chapters 13–14 describe the fundamentals as well as the recent advances and challenges in these emerging memory technologies. We believe the book will be useful to researchers and students and fulfill the aim with which we began this work. S. N. Piramanayagam Tow C. Chong ix
ACKNOWLEDGMENTS
Data storage—even if it has to be written purely from a materials perspective—is a multidisciplinary. It involves physics, chemistry, and materials science at the fundamental level; and mechanical, chemical, and electrical engineering at the application level. A book of such a multidisciplinary nature cannot be accomplished in an authoritative fashion without significant contributions of several kind hearts. First of all, we would like to thank all of the contributing authors: Shiva Prasad (IIT Bombay, India), Kumar Srinivasan (Western Digital, USA), Naoki Honda (Tohoku Institute of Technology, Japan), Kiyoshi Yamakawa (Akita Industrial Technology Center, Japan), Bruno Marchon (HGST, USA), Ganping Ju, William Challener, Yingguo Peng, Mike Seigler, and Ed Gage (Seagate Technology, USA); Jingsheng Chen (NUS, Singapore), Bruce Terris (HGST, USA), and Thomas Thomson (U. Manchester, UK), who represented authors from different parts of the globe; and Rachid Sbiaa, Guchang Han, Viloane Ko, Zaibing Guo, Hao Meng, Allen Poh, Thomas Liew, Jiangfeng Hu, Luping Shi, Rong Zhao, Randall Law, and Sunny Lua from Data Storage Institute (DSI), Singapore. They were very glad to contribute chapters and very cooperative in revising and improving the chapters. Our sincere thanks are due to these authors. There are several others who provided the help and support at the initial stages which motivated us to take this job. Catherine Faduska (formerly of IEEE) and Liesl Folks (HGST, USA) were instrumental in helping with the review and selection of the book proposal. There are several authors who were interested in writing a chapter but could not write because of certain unavoidable circumstances. We acknowledge their support. We also would like to thank IEEE Press and Wiley for their support to publish this work. Personally, S.N.Piramanayagam would like to thank his family members Preeti, Priya, and Pramesh, and colleagues and students in DSI for their support, understanding, and patience during this period. Tow C. Chong would like to dedicate this effort to his family and all the DSI staff. S. N. P. T. C. C.
xi
CONTRIBUTORS
William Challener, Seagate Technology, USA Jingsheng Chen, National University of Singapore, Singapore Tow C. Chong, Data Storage Institute, Singapore Ed Gage, Seagate Technology, USA Zaibing Guo, Data Storage Institute, Singapore Guchang Han, Data Storage Institute, Singapore Naoki Honda, Tohoku Institute of Technology, Japan Jiangfeng Hu, Data Storage Institute, Singapore Ganping Ju, Seagate Technology, USA Viloane Ko, Data Storage Institute, Singapore Randall Law Yaozhang, Data Storage Institute, Singapore Thomas Y. F. Liew, Data Storage Institute, Singapore Sunny Y.H. Lua, Data Storage Institute, Singapore Bruno Marchon, Hitachi GST, USA Hao Meng, Data Storage Institute, Singapore Yingguo Peng, Seagate Technology, USA S. N. Piramanayagam, Data Storage Institute, Singapore Allen Poh Wei Choong, Data Storage Institute, Singapore Shiva Prasad, Indian Institute of Technology-Bombay, India Rachid Sbiaa, Data Storage Institute, Singapore Mike Seigler, Seagate Technology, USA Luping Shi, Data Storage Institute, Singapore Kumar Srinivasan, Western Digital, USA Bruce D. Terris, Hitachi GST, USA Thomas Thomson, The University of Manchester, UK Kiyoshi Yamakawa, AIT, Akita Industrial Technology Center, Japan Rong Zhao, Data Storage Institute, Singapore
xiii
