Electrical resistivity in carrier-doped RNb3O9 (R=La, Ce, Pr and Nd)

✍ Scribed by S. Ebisu; T. Sogabe; M. Hayashi; S. Nagata

• Book ID: 104152250
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 224 KB
• Volume: 61
• Category: Article
• ISSN: 0022-3697
• DOI: 10.1016/s0022-3697(99)00399-6

✦ Synopsis

Carrier doping in insulating compounds RNb 3 O 9 (R La, Ce, Pr and Nd) has been carried out. Electrical resistivities below 300 K were measured for excess R-doped compounds; R 1ϩx Nb 3 O 9 x Յ 0:2 and oxygen-deficient compounds; RNb 3 O 9Ϫy y 0:1: All the samples showed dc conductivity, however the resistivities were very high, e.g. even the lowest value at 300 K is about 1 V cm for CeNb 3 O 8.9 . The resistivities of R 1ϩx Nb 3 O 9 and RNb 3 O 8.9 varied with temperature holding the relation of ln r G T 0 =T 1=4 indicating Mott variable-range hopping (VRH) conductivity. In both systems, the Ce-containing compounds show much lower resistivities. It is noteworthy that the resistivity of CeNb 3 O 8.9 is much lower than the values for the other RNb 3 O 8.9 , two orders in the magnitude at 300 K.