Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Materials Science Poland

2 2007

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Structure and magnetism of Co2CrAl Heusler alloy films

Dubowik J., Gościańska I., Kudryavtsev Y. V., Oksenenko V. A.

Materials Science Poland

2007

Vol. 25, No. 4

1281--1287

We report on magnetic properties of Co2CrAl thin films. Low-field magnetization measurements show that the films with the best B2/L21 structure exhibit ferromagnetic order below the Curie temperature TC ??330-340 K and below 200 K they exhibit magnetic characteristics suggesting the presence of antiferromagnetic ordering. Our ferromagnetic resonance measurements confirm a complex magnetic phase diagram of Co2CrAl due to a disorder between Co and Cr sites in nominally L21 or B2 structures.

Films of Heusler alloys

Dubowik J., Gościańska I., Szlaferek A., Kudryavtsev Y. V.

Materials Science Poland

2007

Vol. 25, No. 2

583--598

Heusler alloys (HA) are a class of materials which may be metals, semiconductors or semimetals, most of them being ferromagnets. Some new applications of HA in spintronics and micro-electromagnetic actuators require their preparation in the form of thin films. Deposition of a HA film is a challenging task from the point of view of its proper ordering. Local disorder and antisite disorder are the most probable reasons of failure in achieving 100% polarization in nanostructures containing HA layers. We will review some examples of tunnel magnetoresistance structures that include Co2YZ HA layers (Y = Mn, Cr, Fe, Z = Al, Si, Ga). The influence of structural ordering on the magnetic and transport properties of Co2MnGa films are given with an emphasis on crystallization process of the films with amorphous structure and a further improvement of its structural ordering. Equally difficult task concerns preparation of HA films with shape memory (SM) effect. Recent achievements in technology of HA with SM will be reviewed. We will focus on non-stoichiometric Ni-Mn-Ga sputtered films. Their SM properties critically depend on composition and post-deposition annealing conditions. By a proper choice of these conditions, the ordered Ni-Mn-Ga films exhibit a well defined SM effect near room temperature.