The development of a thin Cr2O3 wear protective coating for the advanced digital recording system

Solid State Reactions in Cr<sub>2</sub>O<sub>3</sub>-ZnO Nanoparticles Synthesized by Triethanolamine Chemical Precipitation

“…It was observed that the lattice parameter of the ZnO a-axis and c-axis slightly augment as the chromium content increase up to 3 at%. Subsequently, adding more Cr 3+ into the ZnO structure does not substantially modify the lattice parameters, probably as a consequence of cell contraction effect from particle size reduction according to Equation (3). Nevertheless, EDS and IR spectra indicated that chromium atoms are incorporated during the TEA aqueous precipitation in the wurtzite Cr-ZnO solid solution up to 8 at% and do not forms a second phase in the range of room temperature up to 400˚C.…”

“…Chromium (III) nitrate nonahydrate (Cr(NO 3 ) 3 ·9H 2 O, Sigma-Aldrich 99%) and zinc (II) nitrate hexahydrate (Zn(NO 3 ) 2 ·6H 2 O, Sigma-Aldrich 99%) were used as the chromium and zinc ions sources respectively, and triethanolamine N(CH 2 CH 2 OH) 3 (TEA, Sigma-Aldrich 98%) was used as the base in a variation of the procedure reported before for ZnO precipitation [12]. All experiments were carried out by simultaneous addition at 25 mL/s of each metal ion solution, Zn 2+ (aq) and Cr…”

“…ZnO cell expansion in both a and c lattice parameters have been observed on samples prepared by solvothermal synthesis adding up to 8 mol% chromium [21] and in Cr doped ZnO samples prepared by CVS techniques where no second phases besides wurtzite structure have been observed [7], indicating once again that the chromium ions were incorporated in the ZnO structure. The fact that in this process the incorporation of more than 3 at% Cr 3+ ions does not modified any longer the ZnO lattice parameters could be associated to the size effect on lattice parameters given by Equation (3). If chromium ions enter in the cationic sublattice but parameters can not change as a consequence of a smaller particle size, then lattice strain must augment in the crystal structure, as shown before in Williamson-Hall plots and the values reported in Table 1 for parameter η.…”

“…Chromium (III) oxide has a wide range of applications including pigments to reflect infrared radiation [1], heterogeneous catalysts [2], coating materials for thermal protection, wear resistance [3], and so on. It has been established that some spinels have advanced gas sensing and catalytic properties [4], so ZnCr 2 O 4 could be a suitable sensors for aggressive environments because chromium improves the stability of ZnO films against diluted hydrochloric and nitric acid media [5].…”

Preparation of Cr2O3 nanoparticles via C2H5OH hydrothermal reduction

“…Nanoparticles of Cr 2 O 3 are widely applied in fields as catalysts [1], advanced colorants [2], hydrogen sorption materials [3], and wear resistance materials [4]. It is necessary to find an economical process which can be used to prepare them on a large scale.…”