Dresden 2006 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MA: Magnetismus
MA 17: Magnetic Materials II
MA 17.5: Talk
Tuesday, March 28, 2006, 11:15–11:30, HSZ 401
Direct imaging of stripe-like features in La0.75Ca0.25MnO3−y by scanning tunneling microscopy — •Lakshmana Sudheendra1, Vasily Moshnyaga1, Sigrun Koester1, Kai Gehrke1, Bernd Damaschke1, O Shapoval2, A Belenchuk2, and Konrad Samwer1 — 1I. Physikalisches Institut, University of Goettingen, Friedrich-Hund-Platz 1, D-37077, Germany — 2Institute of Applied Physics, Academy of Sciences of Moldova, Academiei Str. 5, MD-2028, Chisinau, Moldova
We have performed high resolution scanning tunneling microscopy (STM) and spectroscopy on pseudo-cubic and orthorhombic La0.75Ca0.25MnO3−y films. In the ferromagnetic regime, we observe stripe-like features for the pseudo-cubic film. The typical stripe dimensions are 3-5 unit cells. This charge-stripe dimension observed under STM is consistent with the length scale of ’correlated polarons’ observed in manganites from various diffraction techniques [1]. The room temperature images show unusual charge modulation at the atomic scale. The formation of stripes and the unusual charge modulations are discussed based on the charge, orbital and the vacancy ordering [2]. The orthorhombic film, on the other hand, shows stripe-like features at room temperature, which is consistent with the stabilization of the polarons due to the greater structural distortion.
Acknowledgement: We acknowledge the support of DFG-SFB 602 TP A2, the Leibniz programm and the A.v Humboldt foundation (L.S)
1. R. Kajimoto et al., Phys. Rev. B 66, 180402(R) (2002) 2. Takashi Hotta et al., Phys. Rev. Lett. 86, 4922 (2001)