Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
권호 표지

Oxygen-Deficient Perovskite, (CaLa) (MgMn)O5.43 Prepared Under Oxygen Gas Pressure of 1 Bar

산소 1기압하에서 합성된 산소결함 Perovskite(CaLa)(MgMn)O$_{5.43}$의 물리화학적 특성연구

  • 최진호 (서울대학교 자연대 화학과) ;
  • 홍승태 (분자과학연구소 무기재료부) ;
  • 김승준 (분자과학연구소 무기재료부)
  • Published : 1991.08.01
Download PDF
⟨ Previous Next ⟩

Abstract

An oxygen deficient perovskite (CaLa)(MgMn)O5.43, with the cubic unit cell parameter of 3.826$\AA$, was prepared 115$0^{\circ}C$ for 10 hrs under the ambient oxygen gas pressure. The average oxidation state of manganese was determined to be 3.86 by the iodometric titration, so that the perovskite could be formulated as (CaLa) ({{{{ { MgMn}`_{ chi } ^{II } }}{{{{ { Mn}`_{ y} ^{III } }}{{{{ { Mn}`_{1- chi -y } ^{IV } }})O5.43 (2x+y=0.14). From X-ray photoelectron spectroscopy, the manganese ions in the lattice are mostly tetravalent, but two paramagnetic configurations were observed in the EPR spectrum: One sharp isotropic signal with hyperfines (ΔH 50 G, g=1.997$\pm$0.002 and │A│=82(4)$\times$10-4 cm-1) and a broad isotropic one (ΔH 1600 G, g=1.994$\pm$0.002), those which correspond respectively to Mn(II) and Mn(IV) ions. According to the magnetic susceptibility measurement, it follows the Curie-Weiss law from 20 K up to room temperature with $\mu$eff=5.23 $\mu$B, which is relatively larger than spin-only value({{{{ { mu }`_{eff} ^{s.o } }}=4.04 $\mu$B) due to the effect of weak ferromagnetic coupling. Such a result is in accord with a theory of semicovalence exchange.

Keywords

References

  1. Phys. Rev. v.164 no.779 Magnetic study of the manganate phases: CaMnO₃Ca₄Mn₃$O_{10}, Ca₃Mn₂O_7,Ca₂MnO₄$ J.B. Machesney;N.J. Williams;J.F. Porter;R.C. Sherwood
  2. J. Phys. Soc. Jpn. v.35 no.275 Magnetic structure of the cubic perovskite type strontium manganate(Ⅳ) T. Takeda;S. Ohara
  3. Phys. Rev. v.100 no.2 Neutron diffraction study of the magnetic properties of the series of perovskite-type compounds [(1-x)La, xCa]MnO₃ E.O. Wollan;W.C. Koehler
  4. J. Less-Common Met. v.61 no.133 The preparation and magnetic properties of ternary oxides ABO₃(A=alkaline earth metal, B=titanum, zirconium, manganese, iron, cobalt and quaternary oxides $ATi_{1-y}(Zr_{1-x})BxO₃$ M. Arjomand;D.J. Machin
  5. J. Solid State Chem. v.34 no.1 High-pres-sure synthesis of cubic perovskite CaLaMgMnO? J.H. Choy;G. Demazeau;J.M. Dance
  6. Bull. Kor. Chem Soc. v.12 no.3 Oxygen-deficient perovs-kite, (CaLa)(MgMn)$O_{δ-x}$ prepared under high oxygen gas pressure of 1000 bar J.H. Choy;S.T. Hong
  7. Inorg. Chem. v.2 no.482 Ordering in compounds of the $A(B'_{0.33}Ta_{0.67}$)O₃type F. Galasso;J. Pyle
  8. Acta Crystallogr. v.A32 no.751 Revised effective ionic radii and sys-tematic studies of interatomic distances in halide and chalcogenides R.D. Shannon
  9. Phys Rev. Lett. v.2 no.341 Electron paramagnetic resonance of ma-nganese Ⅳ in SrTiO₃ K.A. Muller
  10. Proc. Phys. Soc. v.92 no.1064 Paramagnetic resonance spectrum of manganese in calcium zirconate B. Henderson
  11. Phys Rev. v.126 no.1684 Sharpline fluorescence, electron paramagnetic resonance, and thermoluminescence of $Mn^{4+}$ in α-Al₂O₃ S. Geschwind;R. Kisliuk;M.P Klein;J.P. Remeika;D.L. Wood
  12. C.R. Acad Sct. v.2 no.16 A new manganese (Ⅳ) oxide: $Sr_{0.5}La_{1.5}Li_{0.5}Mn_{0.5}O₄$ E. Kim;G. Demazeau;J.M. Dance;M. Pouchard;P. Hagenmuller
  13. J. Phys. Chem. So-lids v.51 no.5 A new perovskite-type oxide (BaLa)(MgMn)$O_{6-x}$ (x=0.21) prepared under high oxygen pressure and its physico-chemical characterization J.H. Choy;G. Demazeau;S.H. Byeon;J.M. Dance
  14. Phys. Lett. v.A27 no.114 Spacing of the hyperfine sextet in Mn_{2+}$ E.S.R. in lithium nio-bate (Ⅴ) T. Takeda;A. Watanabe;K. Sugihara
  15. Fiz. Tverd. Tela v.7 no.3688 Electron paramagnetic resonance of $Mn^{4+}$in ZnMoO₄crystals V.F. Dernov-Pigarev;M.M. Zaripov;M.I. Samoilovich;V.G. Stepanov
  16. J. Chem. Phys. v.57 no.973 Use of X-ray pho-toelectron spectroscopy to study bonding in Cr, Mn, Fe and Co compounds J.C. Carver;G.K. Schweitzer
  17. Phys. Rev. v.98 no.2 Theory of ionic or-dering, crystal distortion, and magnetic exchange due to covalent forces in spinel J.B. Goodenough;A.L. Loeb
  18. Phys Rev. v.100 no.564 Theory of role of covalence in the perovskite-type manganites [La, M(Ⅱ)]MnO₃ J.B. Goodenough
  19. Intersci. Magnetochemistry(2nd ed.) P.W. Selwood
  20. Intersci. Introduction to ligand fields B.N. Figgis
  21. Phys Rev. v.82 no.403 Interaction between the d-shells in the transition metals. Ⅱ. Ferromagnetic compounds of manganese with perovskite structure C. Zener
  22. Physica v.1 no.182 The interaction of magnetogenic atoms in paramagnetic crystals H.A. Kramers.