scholarly journals THE EFFECT OF COBALT CONTENT ON MAGNETIC PROPERTIES OF CoFe ALLOYS

2020 ◽  
Vol 5 (2) ◽  
pp. 87-96
Author(s):  
Widia Nursiyanto ◽  
L. Rohman ◽  
M. Alfatun N. ◽  
E. Purwandari
Keyword(s):  
Magnetic Properties ◽  
External Field ◽  
Curie Temperature ◽  
Data Storage ◽  
Cobalt Content ◽  
Disk Drive ◽  
Storage Device ◽  
Temperature Changes ◽  
Atomistic Models ◽  
Coercivity Field

Hard Disk Drive (HDD) as a data storage device when operated with high temperatures (around 66oC), its function will be constrained. The CoFe alloys have a large coercivity field and can be patterned in very small sizes that are suitable for HDD devices. In this study, Co1-x Fex cube alloy was used (x = 0.25; 0.30; 0.50; 0.75). Samples were treated with temperature changes to get the Curie temperature. The coercivity field value is obtained by giving the external field and temperature below Curie temperature and also above Curie temperature to the samples. The VAMPIRE software is a micromagnetic simulation program based on atomistic models. The results showed that Curie’s temperature decreased when Co content increased. The composition of Co0.25 Fe0.75 has the highest Curie temperature that is equal to 1075 K. The temperature Curie is not affected by the size of the cube. When the sample is given a temperature rise below the Curie temperature, the value of the coercivity field decreases.  The value of the coercivity field is very difficult to determine when the temperature used is above the Curie temperature. The percentage of composition does not affect the coercivity field value. Therefore, cube-shaped CoFe material is very suitable for use as a material data storage device operated at temperatures below the Curie.

scholarly journals ANALISIS DIAMETER KRITIS DAN SUHU CURIE BAHAN PARMALLOY FECOB BERBENTUK BOLA-NANO SERTA PENGARUH TEMPERATUR (HEAT ASSISTED) DENGAN MENGGUNAKAN PROGRAM SIMULASI MIKROMAGNETIK NMAG DAN VAMPIRE

2017 ◽  
Vol 2 (3) ◽  
pp. 187-194
Author(s):  
W. Nursiyanto ◽  
L. Rohman ◽  
A. Eko M
Keyword(s):  
Magnetic Properties ◽  
Curie Temperature ◽  
Data Storage ◽  
Base Material ◽  
Critical Diameter ◽  
Hard Disk ◽  
Hysteresis Curve ◽  
Storage Device ◽  
Sufficient Information ◽  
Magnetic Alloy

Abstrak Bahan paduan magnet (parmalloy) FeCoB bersifat magnet kuat karena memiliki koersivitas medan magnetik yang kuat. Dari sifat yang dimiliki ini, FeCoB sangat cocok digunakan sebagai bahan piranti penyimpan data. Namun demikian, bahan parmalloy FeCoB ini akan mengalami perubahan sifat magnetnya ketika mendapat pengaruh temperatur (heat assisted) yang berubah-ubah dan dimensi (diameter bola) yang berbeda. Dengan adanya kondisi tersebut, diperlukan informasi yang cukup dari bahan parmalloy FeCoB agar menjadi efektif dan efisien ketika bahan ini digunakan sebagai bahan dasar hard-disk. Oleh karena itu, dilakukan analisis bahan parmalloy FeCoB yang terdiri dari dimensi diameter yang mempengaruhi perubahan sifat magnet (diameter kritis), suhu Curie akibat perubahan temperatur dan diameter bahan, serta kurva histerisisnya. Penelitian ini dilakukan dengan menggunakan program simulasi mikromagnetik Nmag dan Vampire. Hasil yang didapatkan dari bahan parmalloy FeCoB ini adalah memiliki diameter kritis sebesar 10 nm dan suhu Curie sebesar 700 K. Dari hasil ini dapat disimpulkan bahwa bahan parmalloy FeCoB akan efektif dan efisien sebagai bahan dasar hard-disk bila dimensi diameter yang digunakan di bawah diameteri kritis dan dioperasikan di bawah suhu Curie.   Kata-kata kunci: parmalloy, kurva histerisis, suhu Curie, heat assisted. Abstract The  magnetic alloy material (parmalloy) FeCoB is strongly magnetic material category because it has strong coercivity. So, FeCoB is suitable for use as data storage device. However, the FeCoB will be changed of its magnetic properties when it used to varying temperatures (heat assisted) and different dimensions (spherical diameter). Therefore, some sufficient information is required from the material when this material is used as a hard-disk base material. An analysis of FeCoB parmalloy material consisting of diameter dimensions influencing the change of magnetic properties (critical diameter), Curie temperature due to changes in temperature and material diameter, and hysteresis curve. This research was using simulation of program micromagnetic  are Nmag and Vampire. The results of this research are the critical diameter is 10 nm and value of Curie temperature is 700 K. The conclusion from that results is the material will be effective and efficient as the hard-disk base material when the diameter dimension is used under critical diameter. And it will be operated under Curie temperature. Keywords: parmalloy, hysterisis curve, Curie temperature, heat assisted.

Electrolytic Hydriding of La(Fe, Si)13 Based Materials and its Magnetocaloric Effect

2014 ◽  
Vol 809-810 ◽  
pp. 443-448 ◽  
Author(s):  
Kun Yang ◽  
Na Tian ◽  
Cai Yin You
Keyword(s):  
Phase Transition ◽  
Magnetic Properties ◽  
External Field ◽  
Curie Temperature ◽  
Surface Morphology ◽  
Order Phase Transition ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Second Order Phase Transition

In this paper, the hydriding of La (Fe, Fe)13 based alloys was realized by the electrolytic method and the effect of electrolytic temperature on the hydriding was investigated. The phase components and surface morphology were analyzed by XRD and SEM. The magnetic properties of samples were characterized using VSM. Results showed that the electrolytic hydriding process was enhanced by increasing the electrolytic temperature. The Curie temperature was increased from 196 K to 325 K. Through Arrot-plot analyses, it was found that the phase transition of samples tends to be a second order phase transition. The magnetic entropy change was reduced from 8.03 J/(kg•K) to 2.03 J/(kg•K) under a maximum external field of 1.5 T.

Determination of the Size of an Imaging Data Storage Device at a Full PACS Hospital

2000 ◽  
Vol 42 (4) ◽  
pp. 705
Author(s):  
Soon Joo Cha ◽  
Yong Hoon Kim ◽  
Gham Hur
Keyword(s):  
Data Storage ◽  
Storage Device ◽  
Imaging Data

Perangkat keras komputer

2020 ◽  
Author(s):  
Roudati jannah
Keyword(s):  
Data Storage ◽  
Central Processing Unit ◽  
External Memory ◽  
Storage Device ◽  
Input Device ◽  
Processing Unit ◽  
Central Processing ◽  
Output Device

Perangkat keras komputer adalah bagian dari sistem komputer sebagai perangkat yang dapat diraba, dilihat secara fisik, dan bertindak untuk menjalankan instruksi dari perangkat lunak (software). Perangkat keras komputer juga disebut dengan hardware. Hardware berperan secara menyeluruh terhadap kinerja suatu sistem komputer. Prinsipnya sistem komputer selalu memiliki perangkat keras masukan (input/input device system) – perangkat keras premprosesan (processing/central processing unit) – perangkat keras luaran (output/output device system) – perangkat tambahan yang sifatnya opsional (peripheral) dan tempat penyimpanan data (storage device system/external memory).

Perangkat lunak komputer

2020 ◽  
Author(s):  
Intan khadijah simatupang
Keyword(s):  
Data Storage ◽  
Central Processing Unit ◽  
External Memory ◽  
Storage Device ◽  
Input Device ◽  
Processing Unit ◽  
Central Processing ◽  
Output Device

Komputer adalah serangkaian mesin elektronik yang terdiri dari jutaan komponen yang dapat saling bekerja sama, serta membentuk sebuah sistem kerja yang rapi dan teliti. Sistem ini kemudian digunakan untuk dapat melaksanakan pekerjaan secara otomatis, berdasarkan instruksi (program) yang diberikan kepadanya. Istilah Hardware computer atau perangkat keras komputer, merupakan benda yang secara fisik dapat dipegang, dipindahkan dan dilihat. Software komputer atau perangkat lunak komputer merupakan kumpulan instruksi (program/prosedur) untuk dapat melaksanakan pekerjaan secara otomatis dengan cara mengolah atau memproses kumpulan instruksi (data) yang diberikan. Pada prinsipnya sistem komputer selalu memiliki perangkat keras masukan (input/input device system) – perangkat keras pemprosesan (processing/ central processing unit) – perangkat keras keluaran (output/output device system), perangkat tambahan yang sifatnya opsional (peripheral) dan tempat penyimpanan data (Storage device system/external memory).

Analysis of 6T SRAM Cell in Different Technologies

2017 ◽  
Vol MCSP2017 (01) ◽  
pp. 7-10 ◽  
Author(s):  
Subhashree Rath ◽  
Siba Kumar Panda
Keyword(s):  
Low Power ◽  
Data Storage ◽  
Low Voltage ◽  
Random Access ◽  
Storage Device ◽  
Cmos Process ◽  
Process Technology ◽  
Digital Devices ◽  
Noise Margin ◽  
Sram Cell

Static random access memory (SRAM) is an important component of embedded cache memory of handheld digital devices. SRAM has become major data storage device due to its large storage density and less time to access. Exponential growth of low power digital devices has raised the demand of low voltage low power SRAM. This paper presents design and implementation of 6T SRAM cell in 180 nm, 90 nm and 45 nm standard CMOS process technology. The simulation has been done in Cadence Virtuoso environment. The performance analysis of SRAM cell has been evaluated in terms of delay, power and static noise margin (SNM).

scholarly journals Implications of NVM Based Storage on Memory Subsystem Management

2020 ◽  
Vol 10 (3) ◽  
pp. 999
Author(s):  
Hyokyung Bahn ◽  
Kyungwoon Cho
Keyword(s):  
Random Access ◽  
Disk Drive ◽  
Main Memory ◽  
Memory Storage ◽  
Storage Device ◽  
Storage Devices ◽  
Large Memory ◽  
Memory Subsystems ◽  
Non Volatile Memory ◽  
Management Techniques

Recently, non-volatile memory (NVM) has advanced as a fast storage medium, and legacy memory subsystems optimized for DRAM (dynamic random access memory) and HDD (hard disk drive) hierarchies need to be revisited. In this article, we explore the memory subsystems that use NVM as an underlying storage device and discuss the challenges and implications of such systems. As storage performance becomes close to DRAM performance, existing memory configurations and I/O (input/output) mechanisms should be reassessed. This article explores the performance of systems with NVM based storage emulated by the RAMDisk under various configurations. Through our measurement study, we make the following findings. (1) We can decrease the main memory size without performance penalties when NVM storage is adopted instead of HDD. (2) For buffer caching to be effective, judicious management techniques like admission control are necessary. (3) Prefetching is not effective in NVM storage. (4) The effect of synchronous I/O and direct I/O in NVM storage is less significant than that in HDD storage. (5) Performance degradation due to the contention of multi-threads is less severe in NVM based storage than in HDD. Based on these observations, we discuss a new PC configuration consisting of small memory and fast storage in comparison with a traditional PC consisting of large memory and slow storage. We show that this new memory-storage configuration can be an alternative solution for ever-growing memory demands and the limited density of DRAM memory. We anticipate that our results will provide directions in system software development in the presence of ever-faster storage devices.

Suppression of Ferromagnetism in EuxCa1-xB6

2012 ◽  
Vol 190 ◽  
pp. 97-100 ◽  
Author(s):  
V.V. Glushkov ◽  
A.V. Kuznetsov ◽  
I. Sannikov ◽  
A.V. Bogach ◽  
S.V. Demishev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Curie Temperature ◽  
Single Crystals ◽  
Effective Magnetic Moment ◽  
Paramagnetic State ◽  
Low Field ◽  
Wide Range ◽  
Free Ion ◽  
The Eu

We report the magnetic properties of EuxCa1-xB6 single crystals (0.756x1) studied in the wide range of temperatures (1.8-300 K) and magnetic fields (up to 50 kOe). It was found that low field magnetic susceptibility χ (T) follows the Curie-Weiss law χ~(T-Θp)-1 at high temperatures for all the concentrations studied. The effective magnetic moment of the Eu2+ ion estimated from the data diminishes from the free ion value μeff7.93μB (μB - Bohr magneton) for x=1 to μeff7.3μB for x=0.756. A universal behavior of magnetic susceptibility χ~(T-Θ)-α (α=1.5) is detected close to the Curie temperature TC in the paramagnetic state at both metallic (x>xC~0.8) and dielectric (xC.

scholarly journals The Route for Ultra-High Recording Density Using Probe-Based Data Storage Device

NANO ◽  
2015 ◽  
Vol 10 (08) ◽  
pp. 1550118 ◽  
Author(s):  
Lei Wang ◽  
Jing Wen ◽  
CiHui Yang ◽  
Shan Gai ◽  
YuanXiu Peng
Keyword(s):  
Phase Change ◽  
Data Storage ◽  
Electrical Contact ◽  
Crystal Nucleation ◽  
Access Time ◽  
Storage Device ◽  
Electrical Contact Resistance ◽  
Low Energy Consumption ◽  
Modeling Techniques ◽  
Second Period

Phase-change probe memory using Ge2Sb2Te5 has been considered as one of the promising candidates as next-generation data storage device due to its ultra-high density, low energy consumption, short access time and long retention time. In order to utmostly mimic the practical setup, and thus fully explore the potential of phase-change probe memory for 10 Tbit/in2 target, some advanced modeling techniques that include threshold-switching, electrical contact resistance, thermal boundary resistance and crystal nucleation-growth, are introduced into the already-established electrothermal model to simulate the write and read performance of phase-change probe memory using an optimal media stack design. The resulting predictions clearly demonstrate the capability of phase-change probe memory to record 10 Tbit/in2 density under pico Joule energy within micro second period.

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