Manganese‐Doped Zirconia Nanocrystals

Abstract

In recent theoretical work, it was predicted that transition-metal-doped zirconia (ZrO2) can be ferromagnetic at room temperature with a dependence on the metal dopant and its oxidation state and concentration.[1] For experimental verification of these predictions, manganese-doped ZrO2 nanoparticles were synthesized. The synthesis was achieved by the benzyl alcohol route, which led to high-quality nanocrystals with uniform size and shape. The obtained particles present a homogeneous distribution of the magnetic ion. The crystallographic phase was studied by XRD, electron diffraction, and high-resolution TEM. The doping efficiency was determined at the macroscopic level by chemical analysis and at the nanoscale level by electron energy loss spectrometry. The local structure of the manganese ions in the ZrO2 matrix was characterized by electron paramagnetic resonance. Finally, the magnetic properties of the obtained nanocrystals were investigated by susceptibility measurements

Interfacial effect: magnetism in pure ZrO2, ZnO and SiO2 coated core/shell/shell hybrid nanoparticles

“…When ZrO 2 is doped with metal oxides Ferromagnetic ordering was observed for both undoped and metal doped zirconia was reported by Zippel et al [41]. Paramagnetic behavior of transition metal doped zirconia was reported by Clavel et al [42]. In our case coating of ZnO over Zirconium dioxide also having the same S shaped M-H paramagnetic curve with very minute variations.…”

Fabrication and magnetic properties of Fe and Co co-doped ZrO2

“…11 However, experimental results show no clear ferromagnetic signals at room temperature. 12,13 Material quests, especially using insulators such as ZrO 2 , HfO 2 , and Al 2 O 3 , are essential for functional spin-related ceramics. Fe or Co single-ion doped HfO 2 has been reported, and slight hysteresis features mediated by oxygen vacancies were observed.…”

Adjusting the Magnetic Properties of ZrO2:Mn Nanocrystals by Changing Hydrothermal Synthesis Conditions

“…However, the magnetic properties of Mn-doped ZrO 2 are not fully understood. The solubility of TM ions in ZrO 2 host material is fairly low and the magnetic cluster formation is very often responsible for the observed magnetic properties [14,23,24]. No evidence of long-range ferromagnetic ordering was reported in nanoparticles of ZrO 2 doped with Mn prepared either by the coprecipitation method [23] or by the nonaqueous sol-gel approach in benzyl alcohol [14].…”

“…Pucci et al observed two types of magnetic behavior: paramagnetic behavior for pristine nanocrystals and ferromagnetic behavior due to the presence of Mn 3 O 4 phase after calcination [14]. Clavel et al reported paramagnetic behavior for nanosized ZrO 2 :Mn samples prepared by the benzyl alcohol route [24]. Paramagnetic behavior was reported for polycrystalline Y-stabilized tetragonal zirconia with up to 10% of Mn prepared by the solid state method by equilibrium [25].…”

“…For all of the samples, the negative values of the Curie-Weiss temperature θ were determined, which indicates that antiferromagnetic (AF) interactions are predominant in the measured samples. The negative values of the Curie-Weiss temperature have already been reported for ZrO 2 :Mn [14,[23][24][25]. In our paper, we focus on the influence of the synthesis procedure on the resultant magnetic properties, e.g., the Curie-Weiss temperature.…”