Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Nebraska - Lincoln

Si-Hwang Liou Publications

2003

Articles 1 - 4 of 4

Full-Text Articles in Physics

United States Patent: Application Of High Spin Polarization Materials In Two Terminal Non-Volatile Bistable Memory Devices, Bernard Doudin, Andrei Sokolov, Cheol-Soo Yang, Lu Yuan, Sy-Hwang Liou Dec 2003

United States Patent: Application Of High Spin Polarization Materials In Two Terminal Non-Volatile Bistable Memory Devices, Bernard Doudin, Andrei Sokolov, Cheol-Soo Yang, Lu Yuan, Sy-Hwang Liou

Si-Hwang Liou Publications

Disclosed are two terminal bistable memory cells having least two high-spin polarization magnetic material junctions which are separated from one another by electron trap site defect containing insulator. The two terminal bistable memory cells demonstrate stable, low current readable, hysteretic resistance states which are set by the flow of a relatively high, (eg. a milliamp or less), plus or minus polarity D.C. current therethrough, which resistance is monitored by lower magnitude A.C. or D.C. current flow therethrough. Preferred cells have at least one Cr02/Cr203/ CrO2 sequence but typically have multiple Cr0 ...


Fabrication Of Nonepitaxially Grown Double-Layered Fept:C/Feconi Thin Films For Perpendicular Recording, M.L. Yan, Xingzhong Li, L. Gao, Sy_Hwang Liou, David J. Sellmyer, R.J.M Van De Veerdonk, K.W. Wierman Oct 2003

Fabrication Of Nonepitaxially Grown Double-Layered Fept:C/Feconi Thin Films For Perpendicular Recording, M.L. Yan, Xingzhong Li, L. Gao, Sy_Hwang Liou, David J. Sellmyer, R.J.M Van De Veerdonk, K.W. Wierman

Si-Hwang Liou Publications

A noneptaxially grown double-layered thin-film medium of nanocompsite FePt:C with a FeCoNi soft underlayer for high-density perpendicular magnetic recording was fabricated and investigated. Square-shaped perpendicular loops with a remanance ratio nearly equal to one and a coercivity as large as 8.5 kOe were obtained for this ordered FePt:C double-layered medium. The formation of the ordered L10 phase is confirmed by electron diffraction experiments. Transmission electron microscope observations reveal that FePt grains with a uniform size less than 5 nm are embedded in the C matrix and appear to be well isolated. Our results show that nonepitaxially ...


Magnetotransport Properties Of Cro2 Films Down To Single-Grain Sizes, Lu Yuan, Y. Ovchenkov, Andrei Sokolov, C.-S. Yang, Bernard Doudin, Sy_Hwang Liou May 2003

Magnetotransport Properties Of Cro2 Films Down To Single-Grain Sizes, Lu Yuan, Y. Ovchenkov, Andrei Sokolov, C.-S. Yang, Bernard Doudin, Sy_Hwang Liou

Si-Hwang Liou Publications

The magnetotransport properties of CrO2 films down to single-grain sizes have been investigated. The magnetoresistance of highly grain oriented CrO2 (100) films, deposited onto TiO2 (100) substrates using a high pressure cell, has been measured in the temperature range of 1.5–300 K and in magnetic fields up to 6 T. The difference in the magnetoresistance at the low temperature of these samples is related to the value of the residual resistance ratio (RRR = R273 K/R4.2 K) of the samples. The negative magnetoresistance observed in some of these films is likely due ...


Recording Characteristics Of Perpendicular Magnetic Media With Cozrnb, Nifenb, And Exchange-Pinned Nifenb Soft Magnetic Underlayers, Min Zheng, Albert Chekanov, Geon Choe, Kenneth E. Johnson, Lan Gao, Sy_Hwang Liou May 2003

Recording Characteristics Of Perpendicular Magnetic Media With Cozrnb, Nifenb, And Exchange-Pinned Nifenb Soft Magnetic Underlayers, Min Zheng, Albert Chekanov, Geon Choe, Kenneth E. Johnson, Lan Gao, Sy_Hwang Liou

Si-Hwang Liou Publications

The recording performance of perpendicular media with amorphous CoZrNb, nanocrystalline NiFeNb, and exchange-pinned FeMn/NiFeNb soft magnetic underlayers (SULs) has been studied. A method has been proposed to quantify the spike noises from the SUL. We found that media with higher permeability NiFeNb SULs showed 4 db higher signal-to-noise ratio than media with lower permeability CoZrNb SULs. The exchange-pinned NiFeNb SUL suppresses spike noise and offers good recording performance. Furthermore, the recording frequency dependence of dynamic coercivity (Hc) was strongly affected by the use of different SULs. The increase in dynamic Hc with linear density is negligibly small ...