Preparation and luminescence properties of the red phosphor LaMgAl_(11)O_(19):Eu~(3+)

The precursor of Eu3+-doped LaMgAl11O19 was prepared using the gel-combustion method.When the annealing temperature was below 700°C,the materials were in amorphous state,and when the annealing temperature was above 850°C,the La1-xMgAl11O19:xEu3+ materials were in hexagonal phase.The SEM images indicated that the particle size is between 200 and 400 nm with good dispersion.The luminescence properties of La1-xMgAl11O19:xEu3+ in amorphous and crystalline states both have been investigated by emission and excitation spectra.The excitation spectrum of the phosphor at 613 nm is a wide band and a series of sharp peaks,and the strongest band is at blue 465 nm,the second strongest band is at 395 nm.The excitation and emission spectra showed that this phosphor nicely fit in with the widely applied emission wavelengths of ultravioletor blue LED chips.The characteristic spectrum of Eu3+ in LaMgAl11O19 was found at 613 nm(5D0-7F2).With the formation of crystalline materials,the5D0-7F2 transition significantly increased.The LaMgAl11O19:Eu3+ phosphor may be a good candidate phosphor for LED applications.