Effects of the exchange stiffness constant and distribution on the recording characteristics of perpendicular media

Miyashita, Eiichi; Taguchi, Ryo; Funabashi, Nobuhiko; Tamaki, Toru; Okuda, Haruo

doi:10.1109/tmag.2002.801835

Cited by 8 publications

(10 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[29][30][31][32] Previous reports on micromagnetic simulations in recording media with induced exchange stiffness showed a clear drop in anisotropy by increasing the value of Aef. [33,34] Direct calculation or prediction of Aef could be quite complicated for multiphase systems where both phases are FM. This won't be a simple volume average but rather determined by the inverse averaging of the local exchange constants.…”

Section: Resultsmentioning

confidence: 99%

Effect of Exchange Interactions on the Coercivity of SmCo₅ Nanoparticles Made by Cluster Beam Deposition

Akdoğan

Balamurugan

et al. 2013

Adv Funct Materials

View full text Add to dashboard Cite

Single crystal SmCo5 nanoparticles with an average size of 3.5 nm are produced by cluster-beam deposition. When deposited without matrix, the nanoparticles showed a super-paramagnetic behavior with a blocking temperature of 145 K. Dispersion of the SmCo5 nanoparticles in a carbon matrix results in an increase in both the coercivity and the blocking temperature. Room temperature coercivities as high as 12 kOe are obtained for the first time in mono-layers of SmCo5 nanoparticles dispersed in C matrix. δM plots show that the interactions in the samples are of exchange type, which can decrease the overall effective anisotropy and coercivity according to the random-anisotropy model. Coercivity is found to be inversely proportional to the packing density of the particles. SmCo5 nanoparticles with high coercivity are potential candidates for the next generation ultra-highdensity magnetic recording media.

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of Exchange Interactions on the Coercivity of SmCo₅ Nanoparticles Made by Cluster Beam Deposition

Akdoğan

Balamurugan

et al. 2013

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…Pengaruh variasi exchange stiffness terhadap bentuk kurva histeresis dan slope histeresis seperti yang ditunjukkan seperti hasil di atas menunjukkan tipikal yang sama dengan hasil eksperimental penelitian yang dilaporkan sebelumnya [6,7]. …”

Section: Hasil Dan Dikusiunclassified

Kajian Simulasi Mikromagnetik: Ketergantungan Medan Koersif dengan Besaran Intrinsik Nano-Dot Magnetik dengan Anisotropi Tegak Lurus

Purnama

Ismail

Suharyana

2013

JFA

View full text Add to dashboard Cite

IntisariKajian simulasi mikromagnetik magnetisasi reversal pada nano-dot magnetik dengan anisotropi tegak lurus telah dilakukan dengan menyelesaikan persamaan Landau-Lifshitz-Gilbert. Model yang disimulasikan nano-dot bahan magnetik pada unit sel Heat Assisted Magnetic Recording (HAMR) dengan dimensi 50 nm × 50 nm × 20 nm, 4πMS = 2500 gauss, TC = 373 K dan konstanta anisotropi K ⊥ = 5.10 5 erg/cm 3 . Simulasi ini dilakukan untuk mengetahui faktor-faktor fisis yang berpengaruh pada koersifitas dari pengamatan proses magnetisasi reversal. Hasil simulasi menunjukkan medan koersif meningkat sebesar 18% dengan penurunan redaman Gilbert dari α = 1 hingga α = 0,3. Akhirnya, peningkatan medan koesif juga teramati sebesar 32,7% dengan penurunan konstanta exchange stiffness dari A = 1.10 −6 erg/cm hingga A = 1.10 −7 erg/cm. ABSTRACTMicromagnetic magnetization reversal simulation study of magnetic nano-dot with perpendicular anisotropy has been performed by solving the Landau-Lifshiz-Gilbert equation. A model simulated is magnetic nano-dot materials as considering Heat Assisted Magnetic Recording (HAMR) cell units with dimensions of 50 nm × 50 nm × 20 nm, 4πMS = 2500 gauss, TC = 373 K and anisotropy constant K ⊥ = 5.10 5 erg/cm 3 . The simulation was conducted to determine physical factors that affect to coercive field. Simulation results show the coercive field increased by 18% with decreased Gilbert damping constant from α = 1 to α = 0.3. Finally, the increased of coercive field also observed by 32.7% with decreased exchange stiffness constant from A = 1.10 −6 erg/cm to A = 1.10 −7 erg/cm.KATA KUNCI: micromagnetic simulation, hysteresis curve, coercive field, HAMR I. PENDAHULUANKetersediaan bahan magnet dengan anisotropi magnetik tinggi, telah membuka peluang pemanfaatan yang semakin luas di industri teknologi informasi. Tidak hanya sebagai bahan dasar magnet permanen saja, karakteristik bahan yang stabil dengan panas telah membuka peluang pemanfaatan secara luas sebagai unit storage sel memori pada teknologi perekaman, yakni bahan magnet ini dapat diaplikasikan sebagai media perekaman. Artinya, bahan magnet dengan anisotropi tinggi ini tidak akan kehilangan karakter magnet ketika dipattern hingga orde nm akibat efek panas. Terlebih penemuan bahan magnet dengan anisotropi tegak lurus yang secara teori tidak ada pembatasan rasio dimensi sel dalam mem-pattern. Sedangkan teknologi HAMR diyakini sebagai salah satu metode read-write masa depan yang menggantikan teknologi media perekaman saat ini guna menghadirkan kera- * E-MAIL: bpurnama@gmail.com patan penyimpanan data hingga mencapai 10 Tbit/inch 2 [1, 2].Secara eksperimen, telah banyak dilaporkan berbagai metode untuk meningkatkan anisotropi yang terungkap dari besarnya nilai medan koersif ketika proses magnetisasi reversal. Namun demikian, peningkatan medan koersif belum diketahui secara pasti mekanisme. Secara umum, dua parameter fisika yang dianggap sebagai penyebab peningkatan nilai medan koersif domain wall pinning akibat ketidaksempurnaan struktur kristal penyusun la...

show abstract

“…The numbers of grains in the magnetic cluster were evaluated as 1.5, 2.5 and 9 for A ex =0.05, 0.1, 0.2 Â 10 À6 erg/cm, respectively. The recordable bit length becomes longer with A ex because it is impossible to record a shorter bit length than the magnetic cluster size [2]. Fig.…”

Section: Dependence Of Magnetic Cluster Size On Inter-granular Exchanmentioning

confidence: 99%

“…The authors investigated the relationship between anisotropy field dispersion, inter-granular exchange stiffness and recording characteristics using micromagnetic simulation based on the Landau-Lifshitz-Gilbert (LLG) equation, in which thermal fluctuation is taken into account. We found that the inter-granular exchange stiffness of a medium is strongly correlated to recording characteristics [2]. This paper describes the investigation of the relationship between recording characteristics, thermal decay and magnetic cluster size.…”

Section: Introductionmentioning

confidence: 96%

Dependence of thermal decay on the magnetic cluster size of perpendicular magnetic recording media

Miyashita¹,

Funabashi²,

Taguchi³

et al. 2005

Journal of Magnetism and Magnetic Materials

Self Cite

View full text Add to dashboard Cite

Effects of the exchange stiffness constant and distribution on the recording characteristics of perpendicular media

Cited by 8 publications

References 4 publications

Effect of Exchange Interactions on the Coercivity of SmCo₅ Nanoparticles Made by Cluster Beam Deposition

Effect of Exchange Interactions on the Coercivity of SmCo₅ Nanoparticles Made by Cluster Beam Deposition

Kajian Simulasi Mikromagnetik: Ketergantungan Medan Koersif dengan Besaran Intrinsik Nano-Dot Magnetik dengan Anisotropi Tegak Lurus

Dependence of thermal decay on the magnetic cluster size of perpendicular magnetic recording media

Contact Info

Product

Resources

About

Effects of the exchange stiffness constant and distribution on the recording characteristics of perpendicular media

Cited by 8 publications

References 4 publications

Effect of Exchange Interactions on the Coercivity of SmCo5 Nanoparticles Made by Cluster Beam Deposition

Effect of Exchange Interactions on the Coercivity of SmCo5 Nanoparticles Made by Cluster Beam Deposition

Kajian Simulasi Mikromagnetik: Ketergantungan Medan Koersif dengan Besaran Intrinsik Nano-Dot Magnetik dengan Anisotropi Tegak Lurus

Dependence of thermal decay on the magnetic cluster size of perpendicular magnetic recording media

Contact Info

Product

Resources

About

Effect of Exchange Interactions on the Coercivity of SmCo₅ Nanoparticles Made by Cluster Beam Deposition

Effect of Exchange Interactions on the Coercivity of SmCo₅ Nanoparticles Made by Cluster Beam Deposition