Phase transitions and magnetic behaviour of R1-xCa1+xCrO4 oxides (RY or Sm) (0=x=0.5)
Por:
Romero J., Saez Puche R., Fernandez F., Martinez J.L., Chen Q., Castro M., Burriel R.
Publicada:
1 ene 1995
Resumen:
The RCaCrO4 (RSm or Y) stoichiometric oxides crystallize with orthorhombic symmetry and space group Bmab. In the case of the SmCaCrO4 at 1073 K a structural phase transition of the type Bmab (orthorhombic) ? I4/mmm (tetragonal) has been observed. Below room temperature at about 190 K a second Bmab?P42/ncm (tetragonal) phase transition has been detected from X-ray diffraction data. The magnetic properties of both SmCaCrO4 and YCaCrO4 reveal the existence of antiferromagnetic ordering above room temperature. The appearance of the ferromagnetic component at the temperature at which the low temperature phase transition takes place has been explained as the result of the canting of the antiferromagnetically ordered chromium sublattice. A field-induced magnetic transition has been observed at 50 K and 14 kOe for SmCaCrO4. The doping of the samarium sublattice, which increases the Ca Sm ratio from 1 to 1.5 to give mixed-valence compounds of the type Sm1-xCa1+xCrO4, yields very important changes in the structural properties. © 1995.
Filiaciones:
Romero J.:
Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
Saez Puche R.:
Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
Fernandez F.:
Departamento de Química Industrial y Polímeros, Escuela Universitaria de Ingeniería Técnica Industrial, Universidad Politécnica de Madrid, E-28012 Madrid, Spain
Martinez J.L.:
Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciónes Científicas, Facultad de Ciencias (C-4), Cantoblanco, Madrid E-28049, Spain
Chen Q.:
Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciónes Científicas, Facultad de Ciencias (C-4), Cantoblanco, Madrid E-28049, Spain
Castro M.:
Instituto de Ciencia de Materiales de Aragón, Consejo Superior de Investigaciónes Cientificas, Universidad de Zaragoza, 50009 Zaragoza, Spain
Burriel R.:
Instituto de Ciencia de Materiales de Aragón, Consejo Superior de Investigaciónes Cientificas, Universidad de Zaragoza, 50009 Zaragoza, Spain
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