Fizika Tverdogo Tela, 2024 Volume 66, Issue 12,Pages 2236–2246(Mi ftt10542)
Semiconductors
Temperature stability of a new type ferromagnetism in a gapless dilute magnetic semiconductor Hg$_{1-x}$Fe$_x$Se ($x$ = 0.009 at%) with extremely low concentration of iron impurities
Abstract:
A new type of ferromagnetism was been studied in a gapless diluted magnetic semiconductor (DMS) Hg$_{1-x}$Fe$_x$Se with an extremely low concentration of impurity iron ($x$ = 0.009 at%), which was previously predicted theoretically. Magnetization measurements at two temperatures ($T_1$ = 5 K, $T_2$ = 300 K) in magnetic fields $H$ = $\pm$ 50 kOe were carried out. For impurity contributions at both temperatures, magnetization curves $M_H(H)$ were obtained with parameters that are characteristic of ferromagnets. It was determined that the sample under study with a minimum iron concentration $N_\mathrm{Fe}$ = 1.8$\cdot$10$^{18}$ cm$^{-3}$ ($x$ = 0.009 at%), in addition to a series of Hg$_{1-x}$Fe$_x$Se single crystals previously studied by us ($x$ = 0.012–0.13 at%), is included in the hybridization interval , in which magnetism of a special type is observed (without inter-impurity interaction). It has been established that the new mechanism of magnetic ordering in a wide temperature range (5–300 K) is due to hybridization effects and exchange interaction of donor conduction electrons, more effective than indirect exchange interaction in conventional DMS (type GaAs:Mn).
Keywords:spontaneous spin magnetism, diluted magnetic semiconductors (DMS), low-concentration $d$-impurities, spin polarization of conduction electrons, spintronics.
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