DocumentCode :
860859
Title :
Magnetic Properties of La 0.7Ca0.3 MnO3 Manganite Bulk and Nanometer-Sized Crystals
Author :
Rozenberg, E. ; Tsindlekht, M.I. ; Felner, I. ; Sominski, E. ; Gedanken, A. ; Mukovskii, Ya.M.
Author_Institution :
Dept. of Phys., Ben-Gurion Univ. of the Negev, Beer-Sheva
Volume :
43
Issue :
6
fYear :
2007
fDate :
6/1/2007 12:00:00 AM
Firstpage :
3052
Lastpage :
3054
Abstract :
AC and DC magnetic measurements in temperature interval 5-300 K and at external magnetic field Hles 5 T were employed to probe and compare magnetic ordering in bulk and nanometer-sized (15plusmn2 nm) La0.7Ca0.3MnO3 single crystals. The respective Curie temperatures (TC)~239 K and 233 K, close to each other are observed in bulk and nano samples. While, their low T spontaneous magnetizations are strongly different, being about 3.6 and 1.2 muB/f.u., respectively. AC susceptibility (chi) of a bulk sample, measured at Hdc=0, shows a maximum of chi(T) at T~TC. In a contrast, chi(T) of the nano-sample demonstrates a broad maximum far below its TC. In the nano-sample both real and imaginary parts of chi are frequency dependent within the 5-280 K range. In a contrary, the frequency dependence is observed only for imaginary part of chi in bulk crystal. It is concluded that the similar ferromagnetic ground state exists in both considered samples; however, it is strongly frustrated in agglomerated nano particles due to surface magnetic disorder and interparticle interactions.
Keywords :
Curie temperature; calcium compounds; ferromagnetic materials; frustration; lanthanum compounds; magnetic particles; magnetic structure; magnetic susceptibility; nanoparticles; spontaneous magnetisation; surface magnetism; 5 to 300 K; AC susceptibility; Curie temperature; La0.7Ca0.3MnO3; agglomerated nanoparticles; bulk manganite crystals; external magnetic fields; ferromagnetic ground states; interparticle interactions; low temperature spontaneous magnetization; magnetic frustration; magnetic ordering; nanometer sized crystals; surface magnetic disorder; Crystallization; Crystals; Magnetic field measurement; Magnetic properties; Physics; Plasma measurements; Plasma temperature; Stationary state; Temperature dependence; Temperature measurement; Magnetic susceptibility; magnetization processes; manganese compounds; nanotechnology;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2007.894360
Filename :
4202893
Link To Document :
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