Effect of annealing conditions on the magnetism of Vanadium-doped TiO2 powders

Synthesis and physical properties of the hollandite‐type titanium oxide KxTi8O16

“…A saturation magnetization for the ferromagnetic component was estimated by subtracting the paramagnetic component from M-H data to be 4 x 10 -3 emu/g. The obtained value is similar to the values in V-doped TiO 2 powders [9], Cr [10] and Co [11] -doped TiO 2 nanoparticles and reduced A and R-type TiO 2 powders [12]. The saturation magnetization corresponds to 4 x 10 -4 μ B per Ti 3+ ion.…”

Room-temperature ferromagnetism of Fe-doped TiO2 nanoparticles driven by oxygen vacancy

“…However, the origin of ferromagnetism in transition metal ions doped TiO 2 have still been controversial. Some papers report on the absence of RTFM on this system [6][7][8], some reports claim that FM arises from clustering or impurity [9,10] while most recent results strongly support intrinsic origin due to the presence of defect such as oxygen vacancies or metal interstitials [11][12][13][14]. These controversial results give an indication that RTFM in O-DMSs is critically dependent on fabrication and growth conditions.…”

Room-temperature ferromagnetism in Ti1−V O2 nanocrystals synthesized from an organic-free and water-soluble precursor

“…After the first discovery of roomtemperature ferromagnetism (RTFM) in Co-doped anatase TiO 2 by Matsumoto et al [2], a great deal of researches have been carried out on the 3d transition metal doped oxide semiconductors, such as ZnO [1,5,6], TiO 2 [3,7], SnO 2 [8,9], etc., which exhibit ferromagnetism above room temperature (RT). However, the origin of FM in these oxide DMSs is still controversial as to whether the ferromagnetism is intrinsically caused by electron spins or it stems from the magnetic precipitations due to the dopant ions segregation, and some reported results are contradictory [7,10,11]. It is therefore vital to clarify the fundamental questions about origin of ferromagnetism in these oxides.…”