We have investigated the magnetic properties of nanocrystalline LaCo 0.5Mn0.5O2. The temperature dependence of the imaginary part of the ac susceptibility shows a strongly frequency-dependent maximum at a temperature Tf, which is well below the ferromagnetic transition temperature (Tc∼230 K). The frequency dependence of Tf obeys the Arrhenius relation, f = fo exp(-E a/kBT), with physically reasonable values of f o = 109 Hz and Ea/kB = 1518 K. The frequency shift of Tf per decade of frequency is one of the highest values observed in any magnetic system, and a similarly large value is also found in LaCO0.4Mg0.1Mn0.5O3, Suggesting that such behavior is intrinsic despite the apparent presence of long-range ferromagnetic order.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jan 1 2003|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics