Article

# Modification of the ground state in Sm-Sr manganites by oxygen isotope substitution

University of Groningen, Groningen, Groningen, Netherlands
(Impact Factor: 3.66). 09/2002; 67(10). DOI: 10.1103/PhysRevB.67.100410
Source: arXiv

ABSTRACT

The effect of $^{16}$O $\to$ $^{18}$O isotope substitution on electrical resistivity and magnetic susceptibility of Sm$_{1-x}$Sr$_x$MnO$_3$ manganites is analyzed. It is shown that the oxygen isotope substitution drastically affects the phase diagram at the crossover region between the ferromagnetic metal state and that of antiferromagnetic insulator (0.4 $< x <$ 0.6), and induces the metal-insulator transition at for $x$ = 0.475 and 0.5. The nature of antiferromagnetic insulator phase is discussed. Comment: 4 pages, 3 eps figures, RevTeX, submitted to Phys. Rev. Lett

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Available from: N. A. Babushkina, Sep 07, 2015
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##### Article: Field-induced phase transitions in isotope enriched (Sm1-xSrxMnO3)-O-16,18
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ABSTRACT: Doped perovskite manganites Ln1−x(Ca,Sr)xMnO3 are characterised by strong interplay of electron, lattice and spin degrees of freedom. Its ground state ranges from antiferromagnetic insulator to a ferromagnetic metal and strongly depends on many parameters such as temperature, external field, chemical composition, oxygen isotope content, etc. In this work magnetic properties of the compound Sm1−xSrxMn16O3 together with its isotopically substituted counterpart Sm1−xSrxMn18O3 (90% of ) were studied under magnetic field up to in the temperature range 4–. We have performed magnetisation and susceptibility isothermal field scans alongside with study of transport properties. Several sharp magnetic phase transitions were observed, and H–T phase diagram was reconstructed. It was found that oxygen isotope substitution significantly modifies the phase diagram in such a way, that the transition fields shift up to the higher values in the samples with the heavier oxygen masses.
Full-text · Article · Apr 2004 · Physica B Condensed Matter
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##### Article: Crystal and magnetic structure of the SM0.55Sr0.45MnO3 and (Nd0.545Tb0.455)(0.55)Sr0.45MnO3 manganites
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ABSTRACT: Neutron diffraction data are presented for the 152Sm0.55Sr0.45MnO3 (SSM) and (Nd0.545Tb0.455)0.55Sr0.45MnO3 (NTSM) manganites. The Nd and Tb contents in the latter composition are such that the average radius of the A cation 〈r A 〉 in these two compounds is the same. The difference in local tolerance factor fluctuations was about 10%. It was found that replacement of a rare-earth cation with leaving 〈r A 〉 unchanged has practically no effect on the structural and transport properties; indeed, both compounds are metals at low temperatures, have the same crystal structure from liquid-helium to room temperature, and exhibit the same pattern of structural distortions at the onset of magnetic ordering. Magnetic moments of Mn ions in both compositions are ferromagnetically ordered at low temperatures, with T C =122 and 90 K for the SSM and NTSM, respectively. Below 80 K, the rare-earth cation moments in NTSM undergo additional ordering. In contrast to compositions that are close in Sr concentration (x Sr=0.4, 0.5), which feature a phase-separated state with a mixture of the ferromagnetic metallic and antiferromagnetic insulator phases, the ground state of both studied compositions with x Sr=0.45 is uniformly ferromagnetic and metallic.
Full-text · Article · Aug 2004 · Physics of the Solid State
• ##### Article: Study of the effects of isotopic substitution 16O → 18O in Sm1 - XSrxMnO3-type (x = 0.45 and 0.50) manganites by powder neutron diffraction
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ABSTRACT: The results of neutron diffraction studies of the effect of the isotopic substitution 16O → 18O in Sm1 − x SrxMnO3-type (x = 0.45 and 0.50) manganites are considered. The parameters of the crystal and magnetic structures of the samples are determined in the temperature range 1.4–300.0 K. It is shown that the isotopic substitution considerably changes the phase diagram of manganites. The results of the earlier macroscopic studies of the same samples are confirmed.
No preview · Article · Nov 2004 · Crystallography Reports