Influence of the valence states of atoms on conducting properties of PrBa{sub 2}Cu{sub 3}O{sub 6+x}

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Materials Research Bulletin

DOI:https://doi.org/10.1016/S0025-5408(97)00078-0· OSTI ID:522372

Romanenko, A I; Zakharchuk, N F; Naumov, N G; Fedorov, V E ^[1]; Paek, U H ^[2]

---

1. Novosibirsk State Univ. (Russian Federation). Inst. of Inorganic Chemistry
2. Gyeongsang National Univ., Chinju (Korea, Republic of). Dept. of Chemistry

Pr{sup 3+} valent state only was discovered in PrBa{sub 2}Cu{sub 3}O{sub 6+x} within the oxygen content range 0.4 {le} x {le} 0.6. Out of this range, Pr{sup 4+} state appears also. All the samples obtained showed insulating behavior of resistivity r(T). In PrBa{sub 2}Cu{sub 3}O{sub 6+x} (0.4 {le} x {le} 0.6), the resistivity is Mott variable-range hopping conduction type and is connected with oxygen disorder only. Out of this range, the localization is much stronger; this increase is due to Pr{sup 4+}/Pr{sup 3+} position disorder. Also, the localization decreases after annealing at room temperature is the result of ordering. Thus, the absence of metallic (and therefore superconducting) state in PrBa{sub 2}Cu{sub 3}O{sub 6+x} is due to the presence of both Pr{sup 4+} and Pr{sup 4+}/Pr{sup 3+} disorder.

• OSTI ID: 522372
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 8 Vol. 32; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
BARIUM OXIDES
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ORDER-DISORDER TRANSFORMATIONS
PRASEODYMIUM OXIDES
STOICHIOMETRY
VALENCE