Structural and magnetic properties of RTiNO2 (R=Ce, Pr, Nd) perovskite nitride oxides

Authors

Spencer H. Porter, University of WollongongFollow
Zhenguo Huang, University of WollongongFollow
Zhenxiang Cheng, University of WollongongFollow
Maxim Avdeev, ANSTO
Zhixin Chen, University of WollongongFollow
S X. Dou, University of WollongongFollow
Patrick M. Woodward, Ohio State University, University of Wollongong

RIS ID

99729

Publication Details

Porter, S. H., Huang, Z., Cheng, Z., Avdeev, M., Chen, Z., Dou, S. & Woodward, P. M. (2015). Structural and magnetic properties of RTiNO₂ (R=Ce, Pr, Nd) perovskite nitride oxides. Journal of Solid State Chemistry, 226 279-285.

Abstract

Neutron powder diffraction indicates that CeTiNO₂ and PrTiNO₂ crystallize with orthorhombic Pnma symmetry (Ce: a=5.5580(5), b=7.8369(7), and c=5.5830(4) Å; Pr: a=5.5468(5), b=7.8142(5), and c=5.5514(5) Å) as a result of a^-b⁺a^- tilting of the titanium-centered octahedra. Careful examination of the NPD data, confirms the absence of long range anion order in both compounds, while apparent superstructure reflections seen in electron diffraction patterns provide evidence for short range anion order. Inverse magnetic susceptibility plots reveal that the RTiNO₂ (R=Ce, Pr, Nd) compounds are paramagnetic with Weiss constants that vary from -28 to -42 K. Effective magnetic moments for RTiNO₂ (R=Ce, Pr, Nd) are 2.43 μ_B, 3.63 μ_B, and 3.47 μ_B, respectively, in line with values expected for free rare-earth ions. Deviations from Curie-Weiss behavior that occur below 150 K for CeTiNO₂ and below 30 K for NdTiNO₂ are driven by magnetic anisotropy, spin-orbit coupling, and crystal field effects.