Coupled Granular/Continuous Media – Results and Challenges

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2661-2668
Author(s):  
Horia Gavrila ◽  
Doina Elena Gavrila
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Magnetic Recording ◽  
Granular Media ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Theoretical Limit ◽  
Perpendicular Recording ◽  
Perpendicular Magnetic Recording ◽  
Longitudinal Recording

ABSTRACTWhile the most promising longitudinal recording systems cannot surpass the theoretical limit of about 200 Gb/in2 for areal recording density and the demand for higher densities is permanently increasing, the perpendicular magnetic recording constitutes the realistic issue to the longitudinal one. The perpendicular magnetic recording offers significant advantages, the most important being stronger write and read fields, and therefore the use of media of higher anisotropy, smaller grain size, higher signal-to-noise ratio, and a better thermal stability. Unfortunately, the perpendicular recording has to cope some important physical and technological difficulties. To overcome them, many ingenious solutions were proposed. In this paper the coupled granular/continuous (CGC) media, a subtle association of the continuous and, respectively, granular media, are analysed from the viewpoint of their magnetic and recording properties. The challenges and possible improvements of CGC media are discussed.

Head Instability Detection for Testing Process in Perpendicular Magnetic Recording System

2013 ◽  
Vol 770 ◽  
pp. 319-322 ◽  
Author(s):  
Piya Kovintavewat ◽  
Santi Koonkarnkhai ◽  
Aimamorn Suvichakorn
Keyword(s):  
Magnetic Recording ◽  
Signal To Noise Ratio ◽  
Disk Drive ◽  
Detection Algorithm ◽  
Recording System ◽  
High Signal ◽  
Signal To Noise ◽  
Perpendicular Magnetic Recording ◽  
Read Head ◽  
Pass Through

During hard disk drive (HDD) testing process, the magneto-resistive read (MR) head is analyzed and checked if the head is defective or not. Baseline popping (BLP) is one of the crucial problems caused by head instability, whose effect can distort the readback signal to the extent of causing possible sector read failure. Without BLP detection algorithm, the defective read head might pass through HDD assembling process, thus producing an unreliable HDD. This situation must be prevented so as to retain customer satisfaction. This paper proposes a simple (but efficient) BLP detection algorithm for perpendicular magnetic recording systems. Results show that the proposed algorithm outperforms the conventional one in terms of both the percentage of detection and the percentage of false alarm, when operating at high signal-to-noise ratio.

Overcoming the Trilemma Issues of Ultrahigh Density Perpendicular Magnetic Recording Media by L10-Fe(Co)Pt Materials

SPIN ◽  
2015 ◽  
Vol 05 (01) ◽  
pp. 1530002
Author(s):  
Fang Wang ◽  
Hui Xing ◽  
Xiaohong Xu
Keyword(s):  
Thermal Stability ◽  
Magnetic Recording ◽  
Signal To Noise Ratio ◽  
Magnetic Recording Media ◽  
Perpendicular Magnetic Recording ◽  
Materials Engineering ◽  
High Anisotropy ◽  
Superparamagnetic Limit ◽  
Ultrahigh Density ◽  
The Impact

L10-ordered FePt and CoPt (collectively called L10- Fe ( Co ) Pt in this review) have become potential materials for future ultrahigh density perpendicular magnetic recording (PMR) media due to their high magnetocrystalline anisotropy, rendering small grains with high thermal stability. However, PMR media using such high anisotropy faces the well-known trilemma issues among thermal stability, signal-to-noise ratio (SNR), and writability. This paper will provide an overview of the impact of L10- Fe ( Co ) Pt on overcoming the superparamagnetic limit and balancing the trilemma issues for ultrahigh density PMR media. Here the research and development of L10- Fe ( Co ) Pt materials will be presented, from the perspectives of enhancing thermal stability, SNR and writability. Furthermore, we will provide some combined approaches to tackle the challenges in balancing the trilemma issues, focusing on materials engineering.

Regular Array of Magnetic Nano-Dots Prepared by Nanochannel Glass Replica Masks

2002 ◽  
Vol 721 ◽  
Author(s):  
Bo Cheng ◽  
Kun Yang ◽  
B. L. Justus ◽  
W. J. Yeh
Keyword(s):  
Data Storage ◽  
Magnetic Recording ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Perpendicular Recording ◽  
Recording Technology ◽  
Sputtering Deposition ◽  
Longitudinal Recording ◽  
Dot Density ◽  
Magnetic Dots

AbstractIn magnetic recording technology, barriers based on fundamental physical limits on the data density are being approached for the current longitudinal recording modes. However, demands for higher data storage density have escalated in recent years. Discrete perpendicular recording is a viable method to achieve 100 Gb per square inch and beyond. We report on the development of a novel technique to fabricate uniform arrays of nano-sized magnetic dots. Uniform arrays of nanometer-sized magnetic dots are obtained by magnetron sputtering deposition through a nanochannel glass replica mask. The platinum replica masks are fabricated using thin film deposition on etched nanochannel glass and contain uniform hexagonally patterned voids with diameters as small as 50 nanometers. The magnetic dot density can be as high as 1011 per square inch. Our method provides a simple yet effective way to create regularly arranged discrete magnetic media that can be used for perpendicular magnetic recording. The magnetic properties of the dots are studied with a vibrating sample magnetometer.

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