Naslov
Blocking of magnetic nano-clusters in Hf-Fe system

Autori
Pajić, Damir ; Babić, Emil ; Zadro, Krešo ; Ristić, Ramir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
ICM 2009 Program and Abstracts / ICM 2009 - Karlsruhe : ICM 2009, 2009, 173-173

Skup
International Conference on Magnetism

Mjesto i datum
Karlsruhe, Njemačka, 26.08.2009. - 31.08.2009

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
magnetic nano-clusters ; amorphous alloy ; magnetic moment blocking ; magnetic anisotropy ; hysteresis

Sažetak
The hafnium-iron amorphous system Hf_{; ; 100− x}; ; Fe_{; ; x}; ; changes from nonmagnetic for x < 30 to magnetic for x ≥ 50. The range of x between these two regimes is of special interest (For x = 43 it was found that the nanometer sized magnetic clusters relax their magnetization thermally over the anisotropy energy barriers, D.Pajic et.al., J.Phys.:Condens.Matter 19(2007)296207 ). Here we investigated in more details the magnetic moment blocking phenomena for x = 35, 40, 43 alloys. The splitting between the measured zero field cooled and field cooled magnetization curves below the so called blocking temperature shows the characteristics of superparamagnetic systems. The magnetic field dependence of blocking temperature for Hf_{; ; 57}; ; Fe_{; ; 43}; ; is logarithmic in wide range of fields. This could be explained within the distribution of energy barrier heights similarly as the exponential temperature dependence of coercive field was explained. For Hf_{; ; 60}; ; Fe_{; ; 40}; ; the behaviour is more complex with two ranges of different logarithmic dependences. For Hf_{; ; 65}; ; Fe_{; ; 35}; ; the blocking temperature is below 2K, which is caused by the lower magnetic anisotropy and decreased cluster sizes due to the lower iron concentration.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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