Role of Fe-Doping Effect in 2-D MoS2 Magnetic Semiconductor

Abstract

Two 2-D Mo1– x Fe x S2 ( $x = 0, 0.01$ ) nanosheets were fabricated by the hydrothermal method. X-ray diffraction shows both samples are formed in hexagonal $\text{P}6_{3}$ /mmc (2H structure) phase with 2-D morphology. Raman spectra displayed that the peak widths were broadening in the iron-doped sample. AC conductivity experiments revealed that both samples obeyed the small polaron hopping model. The activation energies of $x = 0$ are 0.121(3) and 0.066(1) eV above and below 200 K. Similarly, two different activation energies, 0.140(2) and 0.082(1) eV above and below 240 K are also found in $x = 0.01$ sample. The effect of iron-doped may raise the activation energies of small polaron. Diamagnetism and paramagnetism were observed in pure MoS2 and iron-doped sample, respectively. Magnetic hysteresis experiments show no loop in both samples, which is evidence that there was not any magnetic domain formed. For $x = 0.01$ sample, the Brillouin function is conducted to fit the M–H curve. The fit $ $ of the $x = 0.01$ sample is about 0.038(1) $\mu _{B}/f. u$ ., which matched the value of 1% Fe4+ ( $S = 2$ ) ion-doped.