Co/Pt thin film multilayers with strong perpendicular anisotropy and out-of-plane coercivities of 5-11 kOe were magnetically altered in areas of local ion beam interaction. The ion irradiations were performed by ion projection through... more
Bit-recording technologies that can provide areal densities (ADs) [patterned magnetic recording (BPMR) is expected to be one of the new magnetic ADs] of 1 Tera-bit per square inch or higher. To achieve these ADs, the space between tracks... more
Bit‐patterned media at one terabit‐per‐square‐inch (Tb/in2) recording density require a feature size of about 12 nm. The fabrication and characterization of such magnetic nanostructures is still a challenge. In this Letter, we show that... more
![Figure 1 (online colour at: www.pss-rapid.com) Out-of-plane and in-plane hysteresis loops of (a) magnetic layers deposited on Ta/Ru seed layer (PMA tip), (b) without Ta seed layers (as no- PMA tip similar to commercial tip). X-ray diffraction (XRD) confirmed the presence of Ru(0002) and Co(0002) texture perpendicular to the film surface in samples with Ta seed layer [11, 13]. The rocking curve measurements of these samples showed a FWHM (not shown here) of less than 5 degrees, indicating a good crystallographic texture for a polycrystalline film. How- ever, the films without Ta seed layer did not show any XRD peaks, indicating a random crystallographic orienta- tion. It should be mentioned that the properties of the tip and these samples are expected to be negligibly different as the difference in layer thickness has a larger range in which the properties do not change. Figure 2 shows the MFM images of written bits in a perpendicular recording medium at a scan height of 5 nm, for tips with PMA, no PMA (20 nm thick magnetic layer coating), and commer-](https://figures.academia-assets.com/119988613/figure_001.jpg)
![Figure 3 (online colour at: www.pss-rapid.com) (a) SEM image showing the complete view of a MFM tip. Zoomed SEM images of (b) PMA tip, (c) commercial tip, and (d) AFM tip before depo- sition of magnetic materials. In addition, in order to evaluate the improved perform- ance of tips with PMA, MFM measurements were carried out on BPM. The patterned dots were achieved with high resolution electron beam lithography using hydrogen silsesquioxane (HSQ) as resist [17]. The dots were of](https://figures.academia-assets.com/119988613/figure_002.jpg)
Using chemically patterned substrates to suppress thermal placement errors in the directed self-assembly of block copolymer multicylinder linear arrays CORINNE CARPENTER, KRIS DELANEY, GLENN FREDRICKSON, Univ of California -Santa Barbara... more
Bit-patterned media is a novel technology for magnetic data storage that is poised to increase recording density beyond 1 Tb/sq. in. However, a significant concern in BPMR is the stringent requirements for synchronization between write... more
The next generation of hard disk drive technology for data storage densities beyond 5 Tb/in will require single-bit patterning of features with sub-10 nm dimensions by nanoimprint lithography. To address this challenge master templates... more
In bit-patterned media recording (BPMR) systems, two-dimensional (2D) interference, which includes intersymbol and intertrack interference from down- and across-track directions, respectively, increases when the distance between the... more
The fabrication and planarization of patterned magnetic recording media is investigated and the flyability of magnetic recording sliders on a patterned and planarized 65 mm glass disk is investigated a small coupon of patterned media with... more
During the past decade, magnetic recording density of HDD has doubled almost every 18 months. To keep increasing the recording density, there is a need to make the small bits thermally stable. The most recent method using perpendicular... more
Representative hysteresis loop, of H x against M x. b. Representative total field, H x , made up of contributions from the head field gradient and the demagnetising field gradient. c. Representative magnetisation transition, M x. The... more
Bit-patterned media recording (BPMR) is a magnetic data storage solution where the medium is patterned into nanoscale islands, each representing one bit of data. Write errors can occur in BPMR, especially where islands have position,... more
A model and experimental results of a new method for exposing bit arrays with electron beam lithography are presented. The method allows the reduction of the amount of pattern data by orders of magnitude. The method utilises two... more
In an array of closely spaced magnetic islands as in patterned media, magnetostatic interactions play a major role in widening the switching field distribution and reducing the thermal stability. Patterned antiferromagnetically coupled... more
Co/Pt thin film multilayers with strong perpendicular anisotropy and out-of-plane coercivities of 5-11 kOe were magnetically altered in areas of local ion beam interaction. The ion irradiations were performed by ion projection through... more
One of the key problems facing the designer of data storage devices is how to handle the exponential rise in demand for information storage. To enhance the storage capacity of bit-patterned magnetic recording (BPMR) that stores one data... more
Inter-track interference mitigation with two-dimensional variable equalizer for bit patterned media recording AIP Advances 7, 056521 (2017);
To expand an areal density of hard disk drives, bit-patterned magnetic recording (BPMR) using a patterned medium instead of a granular medium as employed in perpendicular magnetic recording is attracting much attention as the... more
Inter-track interference is one of the most severe impairments in bit-patterned media recording system. This impairment can be effectively handled by a modulation code and a multi-head array jointly processing multiple tracks; however,... more
Two-dimensional (2-D) interference is one of the prominent challenges in ultra-high density recording system such as bit patterned media recording (BPMR). The multi-track joint 2-D detection technique with the help of the array-head... more
This paper proposes a utilization of multiple read heads to predict and correct a track mis-registration (TMR) in bit-patterned media recording (BPMR) based on the readback signals. We propose to use the signal energy ratio between the... more
Processing a user’s voice command includes parsing the command to derive the components referred to therein. These identified components or arguments are then mapped to items or objects in the real world in a process known as “grounding.”... more
In this paper, we present a write failure analysis for bit-patterned media recording (BPMR) with formulas derived to calculate its probability for a given set of system parameters. The write failure model derived in this work includes the... more
We report on fabrication of discrete tracks on perpendicular magnetic recording (PMR) media with an e-beam lithographical process. We studied the recording performance of the e-beam media on a spinstand in parallel with conventional PMR... more
Bit patterned media (BPM) is a promising technology for magnetic recording at densities beyond 1 Tbit/in 2 . To be viable, bit patterns must be reliably fabricated over large areas with few defects. One potential route is to employ... more
We report on fabrication of discrete tracks on perpendicular magnetic recording (PMR) media with an e-beam lithographical process. We studied the recording performance of the e-beam media on a spinstand in parallel with conventional PMR... more
A multiturn counter is proposed which is based on domain wall movement. This sensor has a true-power-on functionality and works gear-less. Due to the new design of the multiturn, the drawbacks of the former design, namely the limitation... more
Erasable optical information storage from amorphous rare earth-transition metal (RE-TM) alloys media has led to impressive improvements towards hyper high density recording in the past five years. Write / erase and readout processes are... more
Perpendicular recording may be the most viable, near future, replacement for the longitudinal core technology in ultrahigh-density magnetic disk storage. Central to this mode of recording is a soft underlayer (SUL) which facilitates flux... more
Contact between a slider and bit patterned media (BPM) is investigated using finite element analysis. The effect of contact conditions and material properties at the interface between slider and disk on plastic deformation and temperature... more
The next generation of hard disk drive technology for data storage densities beyond 5 Tb/in will require single-bit patterning of features with sub-10 nm dimensions by nanoimprint lithography. To address this challenge master templates... more
In this paper, a local area influence probabilistic (LAIP) detector for estimating magnetic grain interactions with coded data bits in two-dimensional magnetic recording is combined with a 2-D Bahl-Cocke-Jelinek-Raviv (BCJR)-based... more
![DETECTOR BER COMPARISON BETWEEN LAIP/BCJR AND THE 2-D-PDNP DETECTOR FROM [28], ON DATA TRACKS 1-3](https://figures.academia-assets.com/112930433/table_004.jpg)
In fabricating high areal density magnetic nanostructures for bit patterned magnetic recording media, conventional lithography methods are limited in scaling and often present other challenges, for instance, as etch-damage in case of... more
Influence of nanoholes array geometrical parameters 2 | 30 of high interest for the development of novel magnetic sensors and for thermo-magnetic recording patterned media based on template-assisted deposition techniques.
The size dependence on the switching properties of microstructured Permalloy (Ni 80 Fe 20) ellipses were investigated by magnetoresistance measurements and magnetic force microscopy. Elements with fixed short axes of 1 m, long axes... more
Transition jitter and shape have been studied for "soft" exchange coupled composite (ECC) media and conventional perpendicular media using micromagnetic simulation. A realistic medium having nonuniform grain size has been employed. Media... more
A perpendicular magnetic recording system has been modeled for the purpose of analyzing transition noise, particularly "jitter." Conventional perpendicular media and "soft" exchange coupled composite (ECC) media with a conventional soft... more
Transition jitter and shape have been studied for "soft" exchange coupled composite (ECC) media and conventional perpendicular media using micromagnetic simulation. A realistic medium having nonuniform grain size has been employed. Media... more
A perpendicular magnetic recording system has been modeled for the purpose of analyzing transition noise, particularly "jitter." Conventional perpendicular media and "soft" exchange coupled composite (ECC) media with a conventional soft... more
Skew angle estimation and alleviation based multi-layer perceptron in V-shaped read-head array BPMR systems AIP Advances 13, 025130 (2023);
Currently, researchers have been developing new ultra-high density magnetic recording technologies to meet the exponential growth of data storage demand. One of the main prospective technologies is bit-patterned media recording (BPMR)... more
Surfaces of patterned NiFe strip-shaped thin films of 15-30 nm thickness were modified by nanowires of NiFe oxide. The NiFe oxide was fabricated by the atomic force microscopy ͑AFM͒ nano-oxidation technique. The anisotropy... more
We have examined two unique data error causes for domain wall displacement detection (DWDD) media, dropout and bit shift, using 8-9 modulation and (1, 7)-RLL modulation. We have determined that dropout depends only on the mark length of... more
We have examined two unique data error causes for domain wall displacement detection (DWDD) media, dropout and bit shift, using 8-9 modulation and (1, 7)-RLL modulation. We have determined that dropout depends only on the mark length of... more
The most important limitation for a significant increase of the areal storage density in magnetic recording is the superparamagnetic effect. Below a critical grain size of the used CoCrPt exchange-decoupled granular films the information... more
A reduction in track width of ultra-high density magnetic recording such as bit-patterned media recording (BPMR) results in an increase in areal density. However, the unfortunate appearance of extreme inter-symbol interference (ISI) and... more
![Fig. 3. An error percentage of all considered 64 data patterns in the SRTR BPMR system, which confirms that the fatal patterns consist of [-1 +1 -1] and [+1 -1 +1]. However, when a bit “1” is mixed with a bit “-1” within the 6- dit data pattern, the error percentage becomes higher. Additionally, we found that the worst data pattern (or the fatal pattern) leading to the highest error percentage is either [-1 +1 -1] or [+1 -1 +1]. Accordingly, we propose to employ a rate-4/6 constrained code!’ in the SRTR BPMR system to avoid these fatal patterns. Here, the rate-4/6 constrained code encodes a 4-bit source word into a 6-bit](https://figures.academia-assets.com/106013641/figure_002.jpg)
