Mesoscopic Ordering Effects in Single-Crystalline Thin Films of Lanthanum Manganites

• Authors: Z. Samoilenko , V. Okunev , E. Pushenko , A. Abal'oshev , M. Baran , P. Gierłowski , S. Lewandowski , R. Szymczak
• Languages of publication: EN

Abstracts

EN

We have investigated thin films of lanthanum manganites epitaxially grown by pulsed laser deposition on single-crystalline substrates. X-ray diffraction studies show that the characteristic feature of the investigated films is a superposition of fractions with long range atomic order in the basic single-crystalline matrix, and mesoscopic order in the clusterized structure encompassing the Mn-O layers. A detailed analysis of diffusive scattering shows that the size of metallic clusters and their volume concentration in the dielectric matrix varies. In the case of a small size and concentration, the metallic clusters in low temperature behave as quantum dots and their presence leads to a tunneling mechanism of conductivity with characteristic R(T)= const. In the case of large cluster size, the discrete energy levels become smeared. It appears also that the optical, transport, and magnetic properties of the investigated films depend critically on the distribution of Mn^{2+}, Mn^{3+}, and Mn^{4+} ions in the clusters.

Keywords

EN

75.30.Kz; 75.47.Lx; 61.50.Ks

Discipline

• 61.50.Ks: Crystallographic aspects of phase transformations; pressure effects(see also 81.30.Hd in materials science)
• 75.47.Lx: Magnetic oxides
• 75.30.Kz: Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)(for ferroelectric phase transitions, see 77.80.B-; for superconductivity phase diagrams, see 74.25.Dw)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2004
• Volume: 105
• Issue: 1-2
• Pages: 93-98

Dates

published

2004-01/02

received

2003-09-15

Contributors

author

Z. Samoilenko

• Donetsk Institute for Physics & Technology, National Academy of Sciences of Ukraine (Donetsk), Donetsk, Ukraine

author

V. Okunev

• Donetsk Institute for Physics & Technology, National Academy of Sciences of Ukraine (Donetsk), Donetsk, Ukraine

author

E. Pushenko

• Donetsk Institute for Physics & Technology, National Academy of Sciences of Ukraine (Donetsk), Donetsk, Ukraine

author

A. Abal'oshev

• Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland

author

M. Baran

• Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland

author

P. Gierłowski

• Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland

author

S. Lewandowski

• Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland

author

R. Szymczak

• Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland

References

• 1. J.M.D. Coey, M. Viret, S. von Molnar, Adv. Phys., 48, 167, 1999
• 2. Q. Huang, A. Santoro, J.W. Lynn, R.W. Erwin, J.A. Borchers, J.L. Peng, R.L. Greene. Phys. Rev. B, 55, 14987, 1997
• 3. Z.A. Samoilenko, V.D. Okunev, E.I. Pushenko, T.A. D'yachenko, A. Cherenkov, P. Gierlowski, S.J. Lewandowski, A. Abal'oshev, A. Klimov, A. Szewczyk. Techn. Phys., 48, 250, 2003
• 4. E.L. Nagaev, Usp. Fiz. Nauk, 166, 833, 1996

Identifiers

DOI

10.12693/APhysPolA.105.93