Abstract
We report magnetisation and electron spin resonance (ESR) measurements on the colossal magnetoresistive
manganites La0.67Ca0.33Mn1xFexO3, with x = 0, 0.01, 0.03, 0.06, 0.10, and 0.15, in the vicinity
of their magnetic (TC) and metal-insulator (TMI) transition temperatures. Above TC, the resonance lines
with g ≈ 2 are caused by ferromagnetic metallic clusters exhibiting a double exchange interaction between
Mn3+ Mn4+ ions. The lines were observed with cooling far below both TC and TMI, and were fitted by
the Dysonian line-shape. The temperature dependences of the line-widths exhibited a minimum value at
Tmin ≈ 1.25TC, followed by an increase with further cooling toward TC. The anomalous behaviour of the
line-width below Tmin is due to the appearance of a ferromagnetic metallic phase within the paramagnetic
matrix. The role of phase segregation, in which the compounds are phase-separated into a mixture of
ferromagnetic and paramagnetic regions, is discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 795 - 801 |
| Number of pages | 7 |
| Journal | Materials Science Poland |
| Volume | 24 |
| Publication status | Published - 2006 |
Fields of science
- 104005 Electrochemistry
- 104006 Solid state chemistry
- 104014 Surface chemistry
- 104017 Physical chemistry
- 105113 Crystallography
- 105116 Mineralogy
- 503013 Subject didactics of natural sciences
- 204 Chemical Process Engineering
- 204001 Inorganic chemical technology
- 205016 Materials testing
- 210006 Nanotechnology
- 211104 Metallurgy