Thermal, nonlinear, magnetic and faraday rotation properties of sol-gel diamagnetic glass /NaYF4: Fe, Ho3+: Role of magnetic ions

Highlights: • Hexagonal nanorods NaYF₄: Fe, Ho was synthesized using hydrothermal method and characterized. • Pure NaYF₄: Fe shows diamagnetic, while NaYF₄: Fe, Ho display superparamagnetic behavior. • Transparent NaYF₄: Fe, Ho containing PbO-Bi₂O₃-B₂O₃-SiO₂ glasses were synthesized using sol-gel technique. • Glasses were investigated in terms of thermal stability, nonlinear coefficient, magnetization and Verdet constant. • 2wt.% NaYF₄: Fe, Ho doped glass showed improved thermal stability, nonlinearity magnetization and Verdet constant. -- Abstract: Ho³⁺ owns the biggest magnetic moment, stark splitting of energy and low-symmetry D₂ crystal field which make Ho³⁺ high polarizable and has been studied as dopant in several magnetic crystals. For the first time, Ho³⁺ doped sol-gel synthesized diamagnetic glass for nonlinear, magnetic and magneto optical study was reported. This paper reports the synthesis, structure, morphology and magnetization of hexagonal NaYF₄:Fe, Ho nanorods and importantly, the influence of NaYF₄:Fe, Ho to the thermal, nonlinear, magnetic and Faraday rotation of diamagnetic glasses through varies techniques such as X-ray diffraction, scanning electron microscopy, Raman spectra, Ultraviolet–visible spectra, different scanning calorimetry, thermal mechanical analysis, Z-scan, superconducting quantum interference device magnetometry and Verdet constant measurement. Experimental results discovered that the doping of Ho³⁺ and Fe³⁺ ions disturbed the self-assembly of NaYF₄ while suppressed the length of nanorod. Due to its nanoscale, magnetization of NaYF₄:Fe, Ho changed from diamagnetic to superparamagnetic. The doping of NaYF₄:Fe, Ho increased the thermal stability and third nonlinearity. Glass with different amount of doping presented diamagnetism and paramagnetism due to the strongest magnetic moment, increased polarizability, electron transition of Ho³⁺ and d-d exchange of Fe³⁺ ions in glass matrix. Glass doped 2% of NaYF₄:Fe, Ho glass showed the best magnetic, magneto optical performance and improved thermal stability and nonlinearity which can be ideal candidate for photonics, nonlinear and magneto optical applications.