Ultrafast magnetization dynamics in the half-metallic Heusler alloy Co2Cr0.6Fe0.4Al

✍ Scribed by Jan-Peter Wüstenberg; Daniel Steil; Sabine Alebrand; Tobias Roth; Martin Aeschlimann; Mirko Cinchetti

• Book ID: 104541933
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 529 KB
• Volume: 248
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.201147087

✦ Synopsis

Abstract

Ultrafast demagnetization upon excitation with intense laser pulses has been observed for a variety of ferromagnetic materials. In half‐metals, long demagnetization times are expected due to the band gap for one spin direction. We have investigated the theoretically half‐metallic Heusler alloy Co~2~Cr~0.6~Fe~0.4~Al (CCFA), using the time‐resolved magnetooptical Kerr effect. A demagnetization time in the range of typical transition metal ferromagnets with lower spin polarization has been found, while magnetization recovery proceeds on a slower time scale. The results are discussed in the context of recent models and experimental results. We propose that for Heusler alloys the initial stage of recovery could be a better measure for the spin polarization than the demagnetization time. A simple estimate leads to a bulk spin polarization value of 0.86 for CCFA.