Abstract
Most previous studies of magnetism in various compounds under extreme conditions have been conducted over a wide pressure range at room temperature or over a wide range of cryogenic temperatures at pressures below 20 GPa (200 kbar). We present some of the most recent studies of magnetism over an extended range of temperatures and pressures far beyond 20 GPa, i.e. in regions of pressure-temperature (P-T) space where magnetism has been largely unexplored. Recent techniques have permitted investigations of magnetism in selected 3 d transition metal compounds in regions of P-T where physical properties may be drastically modified; related effects have often been seen in selected doping studies at ambient pressures. We present 57Fe and 129I Mössbauer isotope studies covering the range 300-4 K to sub-megabar pressures in compounds such as Sr2FeO4, LaFeO3 and FeI2, representative of a broad class of 3 d transition metal compounds. At ambient pressure the electronic structure of the transition metal atom in these antiferromagnetic insulators extends from 3 d4 to 3 d6 and has a distinct influence on the pressure evolution of their magnetic properties. Mössbauer studies of these compounds are considered in conjunction with available structural and electrical transport data at pressure.
Original language | English |
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Pages (from-to) | 145-161 |
Number of pages | 17 |
Journal | Il Nuovo Cimento D |
Volume | 18 |
Issue number | 2-3 |
DOIs | |
State | Published - Feb 1996 |
Keywords
- 01.30.Cc
- 62.50
- 71.30
- 72.80.Ga
- 76.80
- Conference proceedings
- High-pressure and shock-wave effects in solids
- Metal-insulator transitions
- Mössbauer effect
- Transition-metal compounds
- other γ-ray spectroscopy