Accession Number:

AD0254505

Title:

BEHAVIOR OF FE(4 PLUS) IN THE SYSTEM SRFEO3-SRTIO3

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR INSULATION RESEARCH

Personal Author(s):

Report Date:

1961-03-01

Pagination or Media Count:

1.0

Abstract:

Perovskites of the system SrFeO3-SrTiO3 were prepared and measurements made of their magnetic and electrical behavior. Chemical analysis showed the percentage of Fe4 to vary from 72.5 for SrFeO3 to about zero for SrFe0.1Ti0.9O3 the rest of the iron is in the Fe3 state. SrFe1-xTixO3 is antiferromagnetic between x equals 0 and x equals 0.9, with a Neel temperature below 60 K. A parasitic ferromagnetic component develops when these compounds are cooled in a magnetic field. Its magnitude depends on the temperature and on the magnetic field applied during cooling. Detailed studies were made on SrFe0.8Ti0.2O3. The conductivity of these perovskites ranged from 10 to the -8th mhocm for x equals 0.01 for x equals 0.0 and shows a marked break at x equals 0.8. SrFeO3 is an ntype semiconductor with the addition of Ti4 the sign of the thermoelectric voltage changes to p type. The activation energy decreases from 0.79 ev for SrTiO3 to 0.05 ev for SrFeO3. The Fe4 content depends on the heat treatment and atmosphere during formation. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE