Determination of Mn valence from X-ray absorption near edge structure and study of magnetic behavior in hole-doped (Nd1-xCax)MnO3 system
Journal
Journal of Solid State Chemistry
Journal Volume
125
Journal Issue
1
Pages
112-115
Date Issued
1996
Author(s)
Abstract
The Mn valence in (Nd 1-x Ca x )MnO 3 (x = 0-0.5) has been successfully determined using Mn 2 p -edge X-ray absorption near edge structure spectra. Moreover, we have measured the magnetic properties across the series (Nd 1-x Ca x )MnO 3 ; the results show that the perovskite NdMnO 3 is an antiferromagnet with two Néel temperatures (T N ) of 14 and 60 K, respectively. By replacement of Nd 3+ with Ca 2+ , the mixed compounds (Nd 1-x Ca x )MnO 3 became ferromagnetic with a Curie temperature of around 130 K (T C ) for x in the range 0.1-0.3. Furthermore, two weak antiferromagnetic transitions with T N 's of around 30 and 75 K, respectively, embedded in the matrix of the ferromagnet have also been discovered in the range x = 0.2-0.3. For x ≧ 0.4, the samples change to antiferromagnetic with T N 's of around 30 K together with a weak broad ferromagnetic transition with T C 's of around 130 K. It is also important to note that the charge-ordering-induced antiferromagnetic transition at the temperature (T CO ) 250 K was observed in the samples of x = 0.4 and 0.5. © 1996 Academic Press, Inc.
Type
journal article