Novel sol–gel fabrication of Yb3+/Tm3+ co-doped β-NaYF4 thin films and investigation of their upconversion properties

An innovative sol–gel process, using a mixture of Na(hfa)·tetraglyme and RE(hfa)₃·diglyme (RE = Y, Yb, Tm) complexes, has been optimized to produce upconverting β-NaYF₄:Yb³⁺/Tm³⁺ thin films.

Upconverting Er3+,Yb3+ activated β-NaYF4 thin films: a solution route using a novel sodium β-diketonate polyether adduct

A new Na(hfa)·tetraglyme adduct has been synthesized and successfully applied, together with the RE(hfa)₃·diglyme (RE = Y, Yb, Er) complexes, in the sol–gel synthesis of upconverting hexagonal NaYF₄:Yb³⁺,Er³⁺ films.

Morphology-controlled synthesis of NiO films: the role of the precursor and the effect of the substrate nature on the films' structural/optical properties

NiO thin films were grown through MOCVD on quartz and LaAlO₃ (001) single crystal substrates. The relationship between the precursor/substrate nature and film properties allowed to define the best conditions to grow good quality NiO films.

Metal-Organic Chemical Vapor Deposition (MOCVD) Synthesis of Heteroepitaxial Pr0.7Ca0.3MnO3 Films: Effects of Processing Conditions on Structural/Morphological and Functional Properties

Calcium-doped praseodymium manganite films (Pr_0.7Ca_0.3MnO₃, PCMO) were prepared by metal-organic chemical vapor deposition (MOCVD) on SrTiO₃ (001) and SrTiO₃ (110) single-crystal substrates. Structural characterization through X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM) analyses confirmed the formation of epitaxial PCMO phase films. Energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) characterization was used to confirm lateral and vertical composition and the purity of the deposited films. Magnetic measurements, obtained in zero-field-cooling (ZFC) and field-cooling (FC) modes, provided evidence of the presence of a ferromagnetic (FM) transition temperature, which was correlated to the transport properties of the film. The functional properties of the deposited films, combined with the structural and chemical characterization collected data, indicate that the MOCVD approach represents a suitable route for the growth of pure, good quality PCMO for the fabrication of novel spintronic devices.

BiFeO3 films doped in the A or B sites: effects on the structural and morphological properties

Metal-Organic Chemical Vapor Deposition (MOCVD) has been applied to the fabrication of BiFeO3 films undoped and doped with Ba or Ti on SrTiO3 (100) and YSZ (100) substrates. The films have been deposited using a multi-metal source, consisting of the Bi(phenyl)3, Fe(tmhd)3 and Ba(hfa)2 tetraglyme or Ti(tmhd)2(O-iPr)2 (phenyl = -C6H5, H-tmhd = 2,2,6,6-tetramethyl-3,5-heptandione; O-iPr = iso-propoxide; H-hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; tetraglyme = CH3O(CH2CH2O)4CH3) precursor mixture. The structural and morphological characterization of films has been carried out using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Chemical compositional studies have been performed by energy dispersive X-ray (EDX) analysis. Structural and morphological characterizations point to the formation of homogeneous and flat surfaces for both undoped and doped BiFeO3 films.