The crystal and electronic structures, optical and magnetic properties of Tb4Al2O9 have been reported. Polycrystalline Tb4Al2O9 was synthesized by a solid state method at 1600 °C for 4 h under N2 atmosphere (0.48 MPa) using AlN as an in situ reducing agent. Tb4Al2O9 is crystallized in the monoclinic crystal system having space group P21/c with a = 0.74831(1) nm, b = 1.05569(1) nm, c = 1.11507(1) nm, β = 108.96(1)0. Tb4Al2O9 was calculated to be a wide band gap semiconductor with indirect band gap energy of about 3.83 eV in fair agreement with the experimental value ∼4.59 eV obtained from the diffuse reflection spectrum. No photoluminescence of Tb3+ could be observed because of large effects of photoionization and concentration quenching of Tb3+ in Tb4Al2O9. Tb4Al2O9 exhibited weak antiferromagnetic interactions with an effective magnetic moment of near that of the Tb3+ free ion.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry