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We have found an enhancement in the magnetic ordering of tellurium as a result of doping it with iron along with an additional doping of a non-magnetic element antimony. A weak ferromagnetism is observed from the magnetization hysteresis which can pave the way for new kinds of magnetic semiconductors. Using the modified solid state approach, we synthesized bulk alloys of Fe-doped tellurium with co-doping of Sb having general form Fe0.05(Te)1-xSbx; x = 0 and 0.03 and analyzed the sample for their structural, electrical and magnetic properties. Electrical resistivity measurements with varying external magnetic field has been carried out and it shows semiconducting nature for both samples. The conduction mechanism in the high temperature region follows small polaron hopping (SPH) model whereas in the low temperature region, variable range hopping (VRH) model is found to fit the data. Traditionally, though tellurium is diamagnetic in nature, x = 0 sample presents itself as a paramagnetic material as evident from the magnetization measurements. On the other hand, x = 0.03 sample has a small hysteresis which is brought about by the substitution of Sb. A negative to positive crossover is observed in the magnetoresistance plot of both samples which can be co-related to transition from variable range hopping mechanism to thermally activated hopping mechanism.

In this study on Fe0.05(SnTe)0.97Sb0.03 bulk alloy, we found signatures of presence of both magnetic glassy state and ferromagnetism. The bulk alloy is prepared by modified solid state technique and the sample is characterized for its structural, electrical and magnetic properties. Electrical resistivity plot shows semiconducting nature of the sample, however below 25 K, a sudden increase in the electrical resistivity value is observed. The transport mechanism is explained on the basis of small polaron hopping (SPH) model and variable range hopping (VRH) model. A large bifurcation observed between zero-field cooled and field-cooled magnetization at low temperature hints towards existence of a magnetic glassy state. M-H curve exhibits hysteresis behaviour for the measurements carried out at 10, 100 and 300 K. However, absence of saturation of the curves at 10 and 100 K suggests co-existence of ferromagnetic and glassy state. Presence of magnetic glassy state can also be confirmed from the Arrott plot and AC Susceptibility measurement. The susceptibility curves are found to undergo relatively small shift of peaks with frequency and theoretical fitting of the data supports presence of a cluster-glass state.

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