| We become very interested in the relationship between the character and the structure of substance, with the improvment of the testing method and the resolution of the test equipmet.With the help of XPS ,Neutron scattering, X-ray scattering, electrical and magnetic measurement of the characture of single crystal from different direction ,we can understand the physical mechanism of the materials nature well.The floating zone method is one of the most effective and advanced international ways for the growth of lager single crystal.This method is charactered with independing of the crucible, the melt only with their own solid contact, thus avoiding unnecessary pollution and also for the growth of the very high melting point materials(high melting point oxide, the carbide, refractory metals and so on. In this paper , we used solid-phase synthesis of powder of LaMnO3Characterized with X-ray diffraction, manufactured feed rod,and then fired.At last we study the growth of high melting point Manganese Oxide LaMnO3 single crystal chaaraterized with X-ray diffraction,ICP element analysis.At first, MnO 2 and La 2 O3 as intial raw materials were pre-sintered .MnO 2 changeg into Mn 2 O3 at the temperature of 600℃for one hour, and La 2 O3 was sintered at 900℃for 10 hours in orde to be dehydrated. The X-ray diffraction of the after sintered raw matrials says the single phase.With the solid phase method,we synthesized the Manganese Oxide powder analysised with X-ray diffraction.The results show that the single phase of rhombohedral Manganese Oxide (LaMnO3+δ)was formed at the temperature of 1200℃for 12 hours .The pesk form X-ray diffraction was With the least-squares method,we cauculate the lattice constant of the sample.The result is a=5.718?; c=10.601?; V=346.62 ?3,similar with that of #PDF 85-2152.At the same time ,with the Rietveld method we refine the date of the X-ray diffraction from the the powder fired at the temperature of 1300℃. LaMnO3+δbelongs to orthorhombic ,Pnma space group and lattice constant is a=5.537?;b=7.845?;c=5.494?.The site of the atom is as follws: La(0.0173,0.25,0.01333),Mn(0,0,0.5),O1(0.497,0.25,-0.0345),O2(0.2107,0.4740,0.18629)。With the tailor-made capsule,we made the rod of Manganese Oxide under the hydrostatic pressure of 340MPa ,and sintered it at different temperature in search of the best sintered condition .After the analysis in four point of shrinkage factor,the growth of grain,X-ray diffraction and the compaction, the condition of 1350℃for 60 hours which is site to growth of the single crystal.In several explorational experiments, we try to the best of the growth the 13.8mm length of crystal rod was fromed (from the melting of the transitional zone) .As the only one peak of the X-ray diffraction from the pice of the growen rod,the single crystal was here. With the Rietveld Method we get the structure date with space group of Pnma,and a a=5.7425?,b=7.699?,c=5.382(6)?.And The site of the atom is La(0.543,0.25,0.0063),Mn(0,0,0),O1(-0.0107,0.25,0.0733),O2(0.3104,0.0385,0.2257)In the process of crystal growth,some of Mn volatiled,became Mn 3 O4 or Mn 7 O13,attaching in the quartz tube,which is assured by the ICP elment analysis saying the stoichiometric of La and Mn is 1.0:0.893 .But the result of the refine of the X-ray date is LaMnO 3 ,so La 2 O3 was possible precipitational.
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