Structural, optical, magnetic and Faraday rotation properties of MnSe2: Eu doped diamagnetic materials: The impact of multi-valence states of Mn and Eu

Highlights: • 80 nm- Mn_1−xEu_xSe₂ nano cubes presented good morphology, structural, optical and magnetic properties. • Incorporation of Eu disturbed self-assembly of MnSe₂ cubes and decreased energy band gap. • Mn_0.9Eu_0.1Se₂ doped diamagnetic glass presented promising emission and nonlinearity properties. • Dipole-dipole and dipole-electron exchange between mixed valence states of Eu and Mn yielded large magnetization. • 3% Mn_0.9Eu_0.1Se₂ doped glass exhibited giant Faraday rotation Verdet constant of 63.998 rad/T/m at 633 nm. -- Abstract: Rare earth ions coupled magnetic, electronic and magneto-optical properties of transition metal dichalcogenides are attractive due to interaction of lattice, spin and electronic degree of freedom. For the first time, Eu doped MnSe₂ nano-cubes were synthesized and characterized, and the influences to structural and properties of Faraday rotating glass were studied. The introduction of mixed valence states of Eu disturbed the self-assembly of MnSe₂ and enhanced the antiferromagnetism due to the vacancies induced by the charge neutral and radius/electronegativity difference. Mn_0.9Eu_0.1Se₂ presenting smaller grain size and better crystallization was selected as dopant to heavy metal oxide glass matrix. The rich energy levels of significant d-d, f-f electron transitions of Mn and Eu ions in Mn_0.9Eu_0.1Se₂ contributed to the improvement of optical linear and nonlinear properties. The band gaps of glasses were decreased and the absorption edges red-shifted. Meanwhile, the third nonlinearity was improved due to increase of polarizability. The spin interactions and electrons charge interactions between Eu and Mn ions in glass provided complex magnetization changing from diamagnetic, paramagnetic and antiferromagnetic. 3% of Mn_0.9Eu_0.1Se₂ functionalized glass showed excellent optical emission at 560 nm and 620 nm wavelengths, good nonlinear coefficient (5.88 × 10⁻¹⁴ esu), high paramagnetic moment (8.28 × 10⁻⁶ emu/mol) and giant Verdet constant value (63.998 rad/T/m at 633 nm).