Small polarons in undoped Nd2CuO4±δ

✍ Scribed by M. Scavini; P. Ghigna; G. Spinolo; U.Anselmi Tamburini; G. Flor

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 550 KB
• Volume: 251
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00373-8

✦ Synopsis

The nature and distribution of the charge carriers in undoped Nd2CuO4± 8 have been investigated by means of conductivity measurements (10 ~< T ~< 300 K) and X-ray absorption spectroscopy (XAS). Whenever it was possible, the conductivity data were obtained at constant carrier concentration, in order to separate the mobility term. In particular, for the T, pO 2 range in which charge carriers are negative ("n" zone), it was shown that charge carriers have to be identified with small polarons, hopping adiabatically. These small polarons are built up by a self-trapped electron on the copper site, resulting in Cu(I) formation, and the hopping preferentially occurs inside the CuO 2 planes.