Author: Henricus P.J. Wijn Publisher: Springer Science & Business Media ISBN: 3642460356 Category : Science Languages : en Pages : 566
Book Description
1' (/>2 die Winkel zwischen den Magnetisierungsrichtungen der Kugeln und der Verbindungslinie der Kugelmittelpunkte bedeuten. 1m Gleichgewicht ist (/>1 = (/>2=0 oder 71:, auBer wahrend der Ummagnetisierung. Wie wir in Ziff. 18 (s. auch Ziff. 66) sehen werden, wird der Zustand (/>1=(/>2=0 bei der Koerzitiv kraft He=-VMs/r3 (fUr sich beruhrende Kugeln -(71:/6) Ms) instabil. Die Magnetisierung dreht sich dann in beiden Kugeln gleichzeitig und irreversibel in die entgegengesetzte Gleichgewichtslage ((/>1 = (/>2 = 71:), wobei (/>1 = - (/>2 ist (Fanning-ProzeB von JACOBS und BEAN!, s. Fig. 13e). II. Magnetisierungsprozesse. 14. Problemstellung. Ein ferro- oder ferrimagnetischer Kristall ist in einem starken Magnetfeld H in dessen Richtung (positive Richtung) homogen magneti siert. Bei kontinuierlicher Feldumkehr kehrt sich auch die Magnetisierung M (im allgemeinen teilweise diskontinuierlich) in die entgegengesetzte Richtung urn, wobei der Vorzeichenwechsel von M normalerweise nicht im Feld H =0, sondern erst in einem Gegenfeld He
Author: K. Baberschke Publisher: Springer ISBN: 3540446109 Category : Science Languages : en Pages : 394
Book Description
The fascinating phenomenon ferromagnetism is far from being fully understood, although it surely belongs to the oldest problems of solid state physics. For any investigation it appears recommendable to distinguish between materials whose spontaneous magnetization stems from localized electrons of a partially ?lled atomic shell and those in which it is due to itinerant electrons of a partially ?lled conduction band. In the latter case one speaks of band-ferromagnetism, prototypes of which are the classical ferromagnets Fe, Co, and Ni. The present book is a status report on the remarkable progress that has recently been made towards a microscopic understanding of band-ferromagnetism as an electron c- relation e?ect. The authors of the various chapters of this book “Band-Ferromagnetism: Ground-State and Finite-Temperature Phenomena” participated as selected - perts in the 242nd WE-Heraeus-Seminar (4-6 October 2000) held under almost the same title in Wandlitz near Berlin (Germany). It was the second seminar of this type in Wandlitz. (The ?rst in 1998 dealt with the complementary topic of the physics of local-moment ferromagnets such as Gd). Twenty-six invited spe- ers from ten di?erent countries together with ?fty-?ve further participants, who presented contributions in form of posters, spent three days together discussing in an enthusiastic and fertile manner the hot topics of band-ferromagnetism.
Author: Amikam Aharoni Publisher: Clarendon Press ISBN: 9780198508083 Category : Science Languages : en Pages : 344
Book Description
The present book is the second edition of Amikam Aharoni's Introduction to the Theory of Ferromagnetism, based on a popular lecture course. Like its predecessor, it serves a two-fold purpose: First, it is a textbook for first-year graduate and advanced undergraduate students in both physics and engineering. Second, it explains the basic theoretical principles on which the work is based for practising engineers and experimental physicists who work in the field of magnetism, thus also serving to a certain extent as a reference book. For both professionals and students the emphasis is on introducing the foundations of the different subfields, highlighting the direction and tendency of the most recent research. For this new edition, the author has thoroughly updated the material especially of chapters 9 ('The Nucleation Problem') and 11 ('Numerical Micromagnetics'), which now contain the state of the art required by students and professionals who work on advanced topics of ferromagnetism. From reviews on the 1/e: '... a much needed, thorough introduction and guide to the literature. It is full of wisdom and commentary. Even more, it is Amikam Aharoni at his best - telling a story... He is fun to read... The extensive references provide an advanced review of micromagnetics and supply sources for suitable exercises... there is much for the student to do with the guidance provided by Introduction to the Theory of Ferromagnetism.' A. Arrott, Physics Today, September 1997
Author: Terunobu Miyazaki Publisher: Springer Science & Business Media ISBN: 3642255833 Category : Science Languages : en Pages : 490
Book Description
This book covers both basic physics of ferromagnetism, such as magnetic moment, exchange coupling, magnetic anisotropy, and recent progress in advanced ferromagnetic materials. Special focus is placed on NdFeB permanent magnets and the materials studied in the field of spintronics (explaining the development of tunnel magnetoresistance effect through the so-called giant magnetoresistance effect).
Author: V. N. Murray Publisher: Nova Publishers ISBN: 9781594543357 Category : Science Languages : en Pages : 378
Book Description
Ferromagnetism is a form of magnetism that can be acquired in an external magnetic field and usually retained in its absence, so that ferromagnetic materials are used to make permanent magnets. A ferromagnetic material may therefore be said to have a high magnetic permeability and susceptibility (which depends upon temperature). Examples are iron, cobalt, nickel, and their alloys. Ultimately, ferromagnetism is caused by spinning electrons in the atoms of the material, which act as tiny weak magnets. They align parallel to each other within small regions of the material to form domains, or areas of stronger magnetism. In an unmagnetised material, the domains are aligned at random so there is no overall magnetic effect. If a magnetic field is applied to that material, the domains align to point in the same direction, producing a strong overall magnetic effect. Permanent magnetism arises if the domains remain aligned after the external field is removed. Ferromagnetic materials exhibit hysteresis. In 2004, it was discovered that a certain allotrope of carbon, nanofoam , exhibited ferromagnetism. The effect dissipates after a few hours at room temperature, but lasts longer at cold temperatures. The material is also a semiconductor. It is thought that other similarly formed materials, of boron and nitrogen, may also be ferromagnetic. This new book rings together leading research from throughout the world.
Author: Richard M. Bozorth Publisher: Wiley-IEEE Press ISBN: Category : Science Languages : en Pages : 992
Book Description
Described as THE classic text on magnetism, FERROMAGNETISM covers the basics of magnetics, as well as in-depth coverage of magnetic materials. IEEE Press has now brought this important cornerstone of magnetics research back into print. Recognized for its breadth of coverage, this book includes information on magnetic phenomenon and theories, magnetic materials, basic magnetization and domain theory, as well as many fundamental expressions, and useful technical data on many materials.
Author: Soshin Chikazumi Publisher: Oxford University Press, USA ISBN: 0199564817 Category : Science Languages : en Pages : 669
Book Description
This book is a textbook for graduate students and researchers who are interested in ferromagnetism. The emphasis is primarily on explanation of physical concepts rather than on a rigorous theoretical treatment.
Author: Henricus P.J. Wijn
Author: Francis Bitter
Author: K. Baberschke
Author: Henricus P. J. Wijn
Author: Amikam Aharoni
Author: Terunobu Miyazaki
Author: V. N. Murray
Author: Henricus P.J. Wijn
Author: Richard M. Bozorth
Author: Soshin Chikazumi