國立高雄大學圖資館 |

Language: English

Back

Magnetization dynamics using ultrash...

Stanford University.

Magnetization dynamics using ultrashort magnetic field pulses.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Magnetization dynamics using ultrashort magnetic field pulses.
Author:	Tudosa, Ioan.
Description:	104 p.
Notes:	Adviser: Joachim Stohr.
Notes:	Source: Dissertation Abstracts International, Volume: 66-08, Section: B, page: 4288.
Contained By:	Dissertation Abstracts International66-08B.
Subject:	Physics, Condensed Matter.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3186411
ISBN:	9780542287138

Magnetization dynamics using ultrashort magnetic field pulses.
Tudosa, Ioan.

Magnetization dynamics using ultrashort magnetic field pulses. - 104 p.

Adviser: Joachim Stohr.

Thesis (Ph.D.)--Stanford University, 2005.

The high-density recording media, both in-plane and perpendicular type, shows a pattern which indicates a high spin momentum dissipation. The perpendicular magnetic recording media was exposed to multiple magnetic field pulses. We observed an extended transition region between switched and non-switched areas indicating a stochastic switching behavior that cannot be explained by thermal fluctuations.

ISBN: 9780542287138Subjects--Topical Terms:

226939
Physics, Condensed Matter.

Magnetization dynamics using ultrashort magnetic field pulses.
LDR:02986nmm _2200301 _450 001 170787
005 20061228142245.5
008 090528s2005 eng d
020 $a 9780542287138
035 $a 00242817
040 $a UnM $c UnM
100 0 $a Tudosa, Ioan. $3 244817
245 1 0 $a Magnetization dynamics using ultrashort magnetic field pulses.
300 $a 104 p.
500 $a Adviser: Joachim Stohr.
500 $a Source: Dissertation Abstracts International, Volume: 66-08, Section: B, page: 4288.
502 $a Thesis (Ph.D.)--Stanford University, 2005.
520 # $a The high-density recording media, both in-plane and perpendicular type, shows a pattern which indicates a high spin momentum dissipation. The perpendicular magnetic recording media was exposed to multiple magnetic field pulses. We observed an extended transition region between switched and non-switched areas indicating a stochastic switching behavior that cannot be explained by thermal fluctuations.
520 # $a The model films consist of very thin crystalline Fe films on GaAs. Even with these model films we see an enhanced dissipation compared to ferromagnetic resonance studies. The magnetic patterns show that damping increases with time and it is not a constant as usually assumed in the equation describing the magnetization dynamics. The simulation using the theory of spin-wave scattering explains only half of the observed damping. An important feature of this theory is that the spin dissipation is time dependent and depends on the large angle between the magnetization and the magnetic field.
520 # $a Two types of magnetic were used, magnetic recording media and model magnetic thin films. Information about the magnetization dynamics is extracted from the magnetic patterns generated by the magnetic field. The shape and size of these patterns are influenced by the dissipation of angular momentum involved in the switching process.
520 # $a Very short and well shaped magnetic field pulses can be generated using ultra-relativistic electron bunches at Stanford Linear Accelerator. These fields of several Tesla with duration of several picoseconds are used to study the response of magnetic materials to a very short excitation. Precession of a magnetic moment by 90 degrees in a field of 1 Tesla takes about 10 picoseconds, so we explore the range of fast switching of the magnetization by precession. Our experiments are in a region of magnetic excitation that is not yet accessible by other methods. The current table top experiments can generate fields longer than 100 ps and with strength of 0.1 Tesla only.
590 $a School code: 0212.
650 # 0 $a Physics, Condensed Matter. $3 226939
650 # 0 $a Physics, Electricity and Magnetism. $3 227483
690 $a 0607
690 $a 0611
710 0 # $a Stanford University. $3 212607
773 0 # $g 66-08B. $t Dissertation Abstracts International
790 $a 0212
790 1 0 $a Stohr, Joachim, $e advisor
791 $a Ph.D.
792 $a 2005
856 4 0 $u http://libsw.nuk.edu.tw:81/login?url=http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3186411 $z http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3186411