2010/04/30 by S. K. Srivastava, P. Léjay, P. Lejay +4 · 73 citations
Chemistry · Materials Science · Physics and Astronomy · #Ab initio #Chemistry #Condensed matter physics #Content (measure theory) #Crystallography #Electronic and Structural Properties of Oxides #Ferromagnetism #Magnetic and transport properties of perovskites and related materials #Magnetism #Materials science #Order (exchange) #Physics #ZnO doping and properties #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.82.193203
published in Physical Review B 82(19) (American Physical Society) · 10 pages, 3 figures
arxiv created 2010/09/28 · openalex publication_date 2010/11/12 · arxiv updated 2011/01/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Ab initio studies have theoretically predicted room-temperature ferromagnetism in crystalline SnO2, ZrO2, and TiO2 doped with nonmagnetic element from the 1A column as K and Na. Our purpose is to address experimentally the possibility of magnetism in both Sn_1\ensuremath-xKxO2 and Sn_1\ensuremath-xCaxO2 compounds. The samples have been prepared using equilibrium methods of standard solid-state route. Our study has shown that both Sn_1\ensuremath-xCaxO2 and Sn_1\ensuremath-xKxO2 structure is thermodynamically unstable and leads to a phase separation, as shown by x-ray diffraction and detailed microstructural analyses with high-resolution transmission electron microscopy. In particular, the crystalline SnO2 grains are surrounded by K-based phase. In contrast to Ca:SnO2 samples, we have obtained a magnetic phase in K:SnO2 ones but no long-range ferromagnetic order. The K:SnO2 samples exhibit a moment on the order of 0.2 \ensuremathμB/K /ion, in contrast to ab initio calculations which predict 3 \ensuremathμB, where K atoms are on the Sn crystallographic site. The apparent contradictions between our experiments and first-principles studies are discussed.