Composition dependent room temperature ferromagnetism and PL intensity of cobalt doped ZnS nanoparticles

Defect induced paramagnetism in lightly doped ZnS:Fe nanoparticles

“…However, all the above authors have reported superparamagnetism and ferromagnetism at higher Fe doping concentrations ranging from 10 to 60 at% and there are no reports on lightly doped ZnS:Fe nanoparticles. Interestingly, in most cases, researchers have reported good magnetic properties in DMS only at lower doping concentrations of other dopants [5,6,12]. The enthusiasm to know the room temperature magnetic state of ZnS nanoparticles at low Fe doping concentrations and also to probe the magnetic nature at microscopic level has led us to undertake the present investigation and we believe that this study along with the earlier reports will be helpful to understand the comprehensive magnetic state of ZnS:Fe nanoparticles.…”

“…Hoffmann et al [23] reported a richly structured luminescence of Fe 3 þ doped ZnS nanoparticles in the near-infrared spectral region, which was assumed to originate from Fe 3 þ [ 4 T 1 -6 A 1 (S)] transition. A general observation is that in all II-VI compound semiconductors doping of Fe quenches the visible photoluminescence [5][6][7].…”

“…Doped ZnS finds applications in photoluminescent, electroluminescent and spintronic devices due to its stability. A number of transition metal ions such as Mn, Cu, Ni, Co, Ag, Pb, Cr and Fe have been successfully doped in ZnS to produce better photoluminescence and magnetic properties [5][6][7]. Recently, diverse results such as room temperature ferromagnetism, superparamagnetism and low temperature ferromagnetism of Fe doped ZnS nanoparticles and thin films have been reported [7][8][9][10][11].…”

Studies on the Zn x Co 1−x S thin films: A facile synthesis process and characteristic properties

“…The occasional thin film reports include the synthesis via spray pyrolysis [11], pulsed laser deposition [12] and chemical bath deposition [13,14]. Other methods used for the synthesis of Zn-Co-S films and nanocrystals include: aqueous method [15], refluxing technique [16], precipitation method [17] and hydrothermal approach [18,19]. Recently cobalt has been found to be a prospective doping material in ZnS as Co 3+ and Co 2+ doping can result into enhanced photoluminescence [1].…”

Optical Properties of Ni2+-, Co2+-, and Mn2+-doped ZnS Nanoparticles Synthesized Using Reverse Micelle Method

“…Table II shows the comparison value of PL intensity ratio among the samples. Poornaprakash et al 35 also reported that PL intensity is enhanced using Co 2+ ion as dopant, exhibiting no other PL center characteristic. As shown in Figure 8a, the excitation spectrum of ZnS:Co 2+ (6%) nanoparticles was unclear because of their relatively lower intensity than the other samples.…”