Structure and Magnetic Properties of Tetravalent Praseodymium Perovskite SrPrO3

✍ Scribed by Yukio Hinatsu; Masahiro Itoh; Norman Edelstein

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 262 KB
• Volume: 132
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7471

✦ Synopsis

The crystal structure of a tetravalent praseodymium perovskite SrPrO 3 has been investigated by powder X-ray diffraction using Rietvelt analysis method; it is orthorhombic (a ‫؍‬ 6.1168(8), b ‫؍‬ 8.5487(9), c ‫؍‬ 5.9857(7) A s ) with the space group Pbnm. The distortion from the ideal cubic perovskite structure for SrPrO 3 is much larger than that for BaPrO 3 ; the octahedral array of oxygen ions about Pr 4؉ is considerably distorted in SrPrO 3 . The magnetic susceptibility measurements of SrPrO 3 show no existence of the magnetic ordering down to 2.0 K. This is in contrast to the result of isomorphous BaPrO 3 which shows an antiferromagnetic transition at 11.5 K. The electron paramagnetic resonance (EPR) spectrum of the Pr 4؉ could be measured by doping it in an isomorphous SrCeO 3 which is diamagnetic and lowering the temperature to 4.2 K. The EPR spectrum was anisotropic, which corresponds to the deviation of the octahedral oxygen coordination symmetry around the Pr 4؉ ion. The g values obtained are discussed in terms of the crystal field theory.