Magnetic and structural properties of NaLnMnWO6 and NaLnMgWO6 perovskites

✍ Scribed by Graham King; Lora M. Wayman; Patrick M. Woodward

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 559 KB
• Volume: 182
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2009.02.033

✦ Synopsis

We have prepared 14 new AA 0 BB 0 O 6 perovskites which possess a rock salt ordering of the B-site cations and a layered ordering of the A-site cations. The compositions obtained are NaLnMnWO 6 (Ln ¼ Ce, Pr, Sm, Gd, Dy, and Ho) and NaLnMgWO 6 (Ln ¼ Ce, Pr, Sm, Eu, Gd, Tb, Dy, and Ho). The samples were structurally characterized by powder X-ray diffraction which has revealed metrically tetragonal lattice parameters for compositions with Ln ¼ Ce, Pr and monoclinic symmetry for compositions with smaller lanthanides. Magnetic susceptibility vs. temperature measurements have found that all six NaLnMnWO 6 compounds undergo antiferromagnetic ordering at temperatures between 10 and 13 K. Several compounds show signs of a second magnetic phase transition. One sample, NaPrMnWO 6 , appears to pass through at least three magnetic phase transitions within a narrow temperature range. All eight NaLnMgWO 6 compounds remain paramagnetic down to 2 K revealing that the ordering of the Ln 3+ cations in the NaLnMnWO 6 compounds is induced by the ordering of the Mn 2+ sub-lattice.