[PDF]    http://dx.doi.org/10.3952/lithjphys.46114

Open access article / Atviros prieigos straipsnis

Lith. J. Phys. 46, 95–99 (2006)


XPS STUDY OF EPITAXIAL LaNiO3−x FILMS
V. Bondarenka, S. Grebinskij, V. Lisauskas, S. Mickevičius, K. Šliužienė, H. Tvardauskas, and B. Vengalis
Semiconductor Physics Institute, A. Goštauto 11, LT-01108 Vilnius, Lithuania
E-mail: bond@pfi.lt

Received 2 December 2005

X-ray photoelectron spectroscopy (XPS) was used to determine the composition and chemical structure of epitaxial LaNiO3−x films obtained by a reactive dc magnetron sputtering. It was found that, in contrast to the samples synthesized by using solid state chemical reactions, the surface Ni/La concentrations ratio is close to the stoichiometric bulk value. The existence of at least three different forms of oxygen in “as grown” films is shown by XPS characterization. XP spectra have also revealed that lattice oxygen and hydroxide species are in cooperation at the film surface. The significant dehydration of both La and Ni hydroxides to corresponding oxides was observed on cleaning film by Ar+ ion bombardment.
Keywords: reactive dc magnetron sputtering, LaNiO3, photoelectron spectroscopy
PACS: 68.47.Gh, 81.15Cd, 82.80Pv


EPITAKSINIŲ LaNiO3−x SLUOKSNIŲ RÖNTGEN’O FOTOELEKTRONINIŲ SPEKTRŲ TYRIMAS
V. Bondarenka, S. Grebinskij, V. Lisauskas, S. Mickevičius, K. Šliužienė, H. Tvardauskas, B. Vengalis
Puslaidininkių fizikos institutas, Vilnius, Lietuva

LaNiO3−x epitaksiniai sluoksniai, gauti magnetroninio garinimo būdu, turi tobulą struktūrą bei didelį elektrinį laidumą. Šiame darbe pateikti minėtų sluoksnių cheminės sudėties bei galimos atskirų elementų segregacijos tyrimo rezultatai Röntgen’o fotoelektroninės spektroskopijos (RFS) metodu.
RFS spektrai buvo registruojami XSAM-800 spektrometru iki ir po bandinių bombardavimo argono jonais. La–Ni junginiuose Ni 2p3/2 smailė persikloja su La 3d3/2 smaile, todėl, interpretuojant RFS spektrus, reikia nagrinėti visą La 3d ir Ni 2p sritį ir, norint gauti informaciją apie atskirus elementus, reikia iš bendro spektro atiminėti arba nikelio, arba lantano dedamąsias.
Tiek iki bombardavimo, tiek ir po jo La/Ni santykis yra lygus 0,95 ± 0,05. Tai rodo, kad gauti kokybiški sluoksniai, atitinkantys reikiamą sudėtį. Pažymėtina, kad, sintetinant panašius sluoksnius kieto kūno cheminių reakcijų metodu, šis santykis lygus maždaug 2,5.


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