A mutual enhancement action between the ferro-/piezoelectric polarization and the photoluminescent performance of rare earth Pr3+ doped (K0.5Na0.5)NbO3 (KNN) lead-free ceramics is reported. After Pr3+ doping, the KNN ceramics exhibit the maximum enhancement of ∼1.2 times in the ferroelectric remanent polarization strength and ∼1.25 times in the piezoelectric coefficient d33, respectively. Furthermore, after undergoing a ferro-/piezoelectric polarization treatment, the maximum enhancement of ∼1.3 times in photoluminescence (PL) was observed in the poled 0.3% Pr3+ doped sample. After the trivalent Pr3+ unequivalently substituting the univalent (K0.5Na0.5)+, A-sites ionic vacancies will occur to maintain charge neutrality, which may reduce the inner stress and ease the domain wall motions, yielding to the enhancement in ferro-/piezoelectric performance. The polarization-induced enhancement in PL is attributed to the decrease of crystal symmetry abound the Pr3+ ions after polarization. The dual-enhancement of the ferro-/piezoelectric and photoluminescent performance makes the Pr3+ doped KNN ceramic hopeful for piezoelectric/luminescent multifunctional devices.

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A core-shell cobalt ferrite/silicon dioxide/europium ion-doped Y 2 O 3 (CoFe 2 O 4 /SiO 2 /Y 2 O 3 :Eu 3+ ) composite was synthesized by a facile layer-by-layer method. Magnetization of the composite under an external magnetic field of approximately 0.25 T enhanced the photoluminescence (PL) intensity by 56%. The remanent magnetization of the CoFe 2 O 4 core increased the excited charge-transfer transition between O 2− and Eu 3+ in the Y 2 O 3 :Eu 3+ shell, thus enhancing the probability of radiative transition ( 5 D 0 → 7 F 2 ) of Eu 3+ ions and leading to enhanced PL. Remanent magnetization is a noncontact, easy-to-operate technique with high growth amplitude and potential for practical application for smart display devices.

Co-ferrite spinel and FeCo alloy core shell nanocomposites and mesoporous systems for multifunctional applications After the core-shell CoFe 2 O 4 @YVO 4 :Eu 3þ composite synthesized through a facile sol-gel method was magnetized under an external magnetic field of 0.25 T for 4 h, an enhancement of $56% in photoluminescence intensity was observed. The remanent magnetization of the CoFe 2 O 4 core increases the intensity of the excited charge transfer transition of VO 4 3À group in YVO 4 :Eu 3þ shell, which may enhance the probability related to the Eu 3þ radiative transition 5 D 0 -7 F 2 , yielding to a high photoluminescence. The obvious remanent-magnetization-induced enhancement in photoluminescence is helpful in developing excellent magnetic/luminescent material for the practical display devices. V C 2013 AIP Publishing LLC. [http://dx.

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