Physics – Condensed Matter – Superconductivity
Scientific paper
2003-10-16
Phys. Rev. B 68, 224418 (2003)
Physics
Condensed Matter
Superconductivity
25 pages, including 5 figures
Scientific paper
10.1103/PhysRevB.68.224418
We report a detailed set of AC magnetic measurements carried out on bulk large grain La-Ca-Mn-O samples extracted from a floating zone method-grown rod. Three samples with $La_{0.78}Ca_{0.22}Mn_{0.90}O_{x}$ stoichiometry but differing in their microstructure were investigated by electrical resistivity and AC susceptibility measurements: (i) a single grain sample, (ii) a sample containing two grains and (iii) a polycrystalline sample. We show that the superimposition of DC magnetic fields during AC magnetic susceptibility measurements is an efficient way for characterizing the magnetic transition of samples with different microstructures. Whereas both single grain and polycrystalline samples display a single susceptibility peak, an additional kink structure is observed in the case of the double grain sample. The temperature dependence of the AC susceptibility measured with superimposed DC magnetic fields is analyzed in the framework of second-order phase transition ideas. The relations between the critical exponents ($\beta + \gamma$ ~ 1.5, $\delta$ ~ 2.5) are found to be close to those of the mean-field model for all samples. This is attributed to the disordering caused by unoccupied Mn sites.
Ausloos Marcel
Cloots Rudi
Dhalenne Guy
Rulmont A.
Vanderbemden Ph
No associations
LandOfFree
AC magnetic behavior of large grain magneto-resistive La0.78Ca0.22Mn0.90Ox materials does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with AC magnetic behavior of large grain magneto-resistive La0.78Ca0.22Mn0.90Ox materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and AC magnetic behavior of large grain magneto-resistive La0.78Ca0.22Mn0.90Ox materials will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-21793