Negative Oxygen Isotope Effect in Manganites with an Ordered Cation Arrangement in a High Magnetic Field
- Moscow State University, Physical Faculty (Russian Federation)
- Russian Research Centre “Kurchatov Institute,” (Russian Federation)
- Moscow State University, Chemical Faculty (Russian Federation)
The oxygen isotope effect in PrBaMn{sub 2}{sup 16-18} O{sub 5.97} manganite with an ordered cation arrangement is studied. The field dependences of magnetic susceptibility and magnetization are measured in the temperature range 100–270 K and magnetic fields up to 32 T. A significant increase in the temperature of the spin-reorientation antiferromagnet–ferromagnet phase transition is detected in samples enriched in heavy oxygen {sup 18}O (negative isotope effect). The transition temperature and the isotope effect depend strongly on the magnetic field. An H–T phase diagram is plotted for samples with various isotope compositions. An analysis of the experimental results demonstrates that the detected negative isotope effect and the giant positive isotope effect revealed earlier in doped manganites have the same nature. The mechanisms of appearance of isotope effects are discussed in terms of the double exchange model under a polaron narrowing of the free carrier band.
- OSTI ID:
- 22749977
- Journal Information:
- Journal of Experimental and Theoretical Physics, Vol. 126, Issue 3; Other Information: Copyright (c) 2018 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
- Country of Publication:
- United States
- Language:
- English
Similar Records
Magnetocaloric effect in manganites
Intrinsic properties of doped lanthanum manganite