New phenomena in ESR spectra of iron ores from Kryvyi Rih deposit

The electron spin resonance (ESR) spectra of iron ores from Kryvyi Rih deposit have been measured at two different temperatures: 295 K and 150 K. Two samples of ores were chosen for investigations: hematite ore of the Inguletsky combine of oxidized ores (sample 1) and hematite ore of the Novokryvorizky combine of oxidized ores (sample 2). The broad absorption lines with resonance field 1.546 kOe (sample1) and 1.453 kOe (sample 2) were observed at 295 K with values of the g-factor equal to 4.417 and 4.668 respectively. The amplitude of this line depends on the temperature. The ESR-signal amplitude increases with a reduction in temperature from 295 K to 150 K: for sample 1 by 21.6% and for sample 2 by 19.4%. The shift of the absorption line from 1.546 kOe to 1.456 kOe was observed with a reduction in temperature for sample 1 and from 1.453 kOe to 1.288 kOe was observed with a reduction in temperature for sample 2. The increase of the g-factor was observed with a reduction in temperature to 4.578 for sample 1 and to 5.390 for sample 2. (Poster)