All issues
Predecessor
24.69
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
-
Article type: Cover
Pages Cover1-
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (13K) -
Article type: Index
Pages Toc1-
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (30K) -
Biao You, An HuArticle type: Article
Session ID: MMS2000-64
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSMagnetic tunnel junctions(MTJ), i.e., structures consisting of two ferromagnetic layers (FM_1 and FM_2), separated by a very thin insulator barrier (I), have recently attracted attention for their large tunneling magnetoresistance (TMR) whichi appears when the magnetization of the ferromagnets of FM1 and FM2 change their relative orientation from parallel to antiparallel in an applied magnetic field. Using an ultrahigh vacuum magnetron sputtering system, a variety of MTJ structures have been explored. Double Hc magnetic tunnel junction, NiFe/Al_2O_3/Co and FeCo/Al_2O_3/Co, were fabricated directly using placement of successive contact mask. The tunnel barrier was prepared by in situ plasma oXidation of thin Al layers sputter deposited. For NiFe/Al_2O_3/Co junctions, the maximum TMR value reaches 6.0% at room temperature, the switch field can be less than 10 Oe and the relative step with is about 30 Oe. The junction resistance chantes from hundreds of ohms to hundreds of kilo-ohms and TMR values decrease monotonously with the increase of applied junction voltage bias (under zero magnetic field). For FeCo/Al_2O_3/Co junctions, TMR values exceeding 7% were obtained ato room temperature. It is surprising that an inverse TMR of 4% was observed in FeCo/Al_2O_3/Co. The physics governing the spin polarization of tunneling electrons remains unclear. Structures, FeMn/NiFe/Al_2O_3/NiFe, in which one of the FM layers is exchange biased with an antiferromagnetic FeMn layer, were also prepared by patterning using optical lithography techniques. Thus, the junctions exhibit two well-defined magnetic states in which the FM layers are either parallel or antiparallel to one another. TMR values of 16% at room temperature were obtained. The switch field and step width are less than 10 Oe and larger than 30 Oe, respectively.View full abstractDownload PDF (575K) -
Chang-Wook Jeong, Won-Cheol Jeong, Seung-Ki JooArticle type: Article
Session ID: MMS2000-65
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn spin-dependent tunneling junctions, Al_2O_3 tunnel barriers have been grown by plasma-assisted atomic layer controlled deposition(PAALD) between two ferromagnetic films. Al was deposited on the bottom ferromagnetic electrodes(Co) by PAALD method, in which DMEAA (Dimethylethylamine alane) was used as a source gas. And then, Al_2O_3 barriers formed through oxidation of the Al films in a pure oxygen rf plasma. A maximum tunneling MR ratio of 25% was obtained in the junction of which insulating barrier thickness was 25 Å.View full abstractDownload PDF (379K) -
C.H. Ho, M.T. Lin, Y.D. Yao, S.F. Lee, Y. Liou, C.K. Lo, D.R. HuangArticle type: Article
Session ID: MMS2000-66
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSSpin-dependet tunnel magnetoresistance of Co/Al_2O_3/Co_x/NiFe was studied as a function of the thickness of Co_x. The thickness (X) of the doped Co was varied between 0.8nm and 2.0nm. An increase in tunneling magnetoresistance ratio from 3.5% to 9% was found for the spin-dependent tunnel junctions with 0.8 nm to 2.0 nm of doped Co_x. The enhanced tunneling magnetoresistance may be attributed to the increasing in the effective polarzation of the tunnel electron due to the spin-filtering effect from the doped material.View full abstractDownload PDF (387K) -
C.K. Lo, Y.H. Wang, C.H. Lai, Y.D. Yao, D.R. HuangArticle type: Article
Session ID: MMS2000-67
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSEpitaxial Permalloy film is grown on Cu/Si(001). The buffer layer of Cu(001)(1×1) can be stabilized on the unreconstructed(1×1) surface mesh of Si(001) by simply rotating 45° to reduce the lattice mismatch, and a Si(001)√<2>×√<2>R45°-Cu surface is therefore resulted. The structure of permalloy (Py) is face center cubic (FCC) with lattice parameter close to FCC-Cu, Thus, the Py mesh can sit directly on the top of reconstructed Cu(001)/Si(001) surface to form FCC-Py(001) epitaxy. The Py(001) film is found to be magnetized in the plane with the easy and hard magnetic axes parallel to Py[010], and Py[100], respectively, The in-plane uniaxial behavior could be due to the smll lattice mismatch which breaks the 4-fold symmetry.View full abstractDownload PDF (283K) -
Samuel.B. Shueh, Tomy XiaoArticle type: Article
Session ID: MMS2000-68
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSAn investigation was conducted to determine if electron gun from Scanning Electron Microscope (abbr.SEM) induces electrostatic discharge (ESD) causing hard disk drive Giant-Magnetoresistive (abbr.GMR hereafter) sensor failure. We used both customer Shippable and returned single-spin valve (〜10 GB / sq.in areal density) head gimbal assembly (Abbr. HGAs) in this study. All shippable parts were first characterized on a magnetic test Spinstand as well as using quasi-static test bed. Results show that GMR sensor will melt as Low as 12 kV with brightness auto-contrast. However, this can not be reproduced consistently with the shippable control group which was subjected to even greater stress twice. We further examined all SEM work and concluded that they are lot dependent. This suggests some devices have sub-threshold ESD stress lebel which become enlarged by electron beam (abbr.E-beam) to become failed devices. We also searched through our archive and tabulated our ESD failures. Most appeared to come from HGAs that had low electrical head output at drive qualification already implying they may have been slightly EOS damaged or marginal. All returned heads for low head output amplitude are likely be destroyed during bombardment of electrons. It is recommended that proper care to connect the sample to ground through shunting to make it charge free is one way to minimize the ESD exposure. Three are those "sub-threshold" stressed GMR films: E-beam becomes a controlled energy source to stress the films as a failure analysis tool. Certain marginal heads when subject to the external field will weaken if not lead to catastrophic ESD failures. On the other hand, "high threshold" GMR heads are more robust.View full abstractDownload PDF (932K) -
Article type: Appendix
Pages App1-
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (82K) -
Article type: Cover
Pages Cover2-
Published: November 16, 2000
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (63K)
- |<
- <
- 1
- >
- >|