Exploring the optical properties of La₂Hf₂O₇:Pr³⁺ nanoparticles under UV and X-ray excitation for potential lighting and scintillating applications

Abstract

New optical material of La2Hf2O7:Pr3+ nanoparticles with efficient luminescence and scintillating properties have drawn a great deal of attention due to the demand for optoelectronic devices and medical theranostics.

On comparison of luminescence properties of La2Zr2O7 and La2Hf2O7 nanoparticles

“…In this study, both undoped and 5% Eu 3+ -doped La 2 Zr 2 O 7 and La 2 Hf 2 O 7 NPs were synthesized using a combined coprecipitation and molten salts synthesis technique ( Figure S1) as reported in our earlier work. 13,22 The undoped La 2 Zr 2 O 7 and La 2 Hf 2 O 7 NPs are designated as LZO and LHO whereas the Eu 3+ doped samples are designated as LZOE and LHOE. The details on the synthesis, characterization, and theoretical methodology adopted for the LZO and LHO NPs are described as Figures S1-S3, respectively.…”

“…These properties make them suitable for scientific and technological applications such as thermal barrier coatings, 1 magnetic materials, 2,3 electrocatalysis, 4,5 sensors, 6 optical materials, 7 solid-oxide fuel cells, 8 high level nuclear waste hosts, 9 etc. Moreover, recently relevant nanostructured pyrochlore materials have gained significant attention compared with their bulk counterparts in the areas of photoluminescence, [10][11][12][13] scintillation, [11][12][13] and magnetism. 14 In this context, La 2 Zr 2 O 7 and La 2 Hf 2 O 7 have been two standout pyrochlores for their suitability in various kinds of technological applications such as luminescence, scintillator, ferroelectric material, nuclear waste host, catalyst, and electrode material in fuel cells, etc.…”

“…14 In this context, La 2 Zr 2 O 7 and La 2 Hf 2 O 7 have been two standout pyrochlores for their suitability in various kinds of technological applications such as luminescence, scintillator, ferroelectric material, nuclear waste host, catalyst, and electrode material in fuel cells, etc. 9,[11][12][13][15][16][17][18][19][20] They are thermally stable, can accommodate dopant ions at both A and B sites, and have high radiation stability, etc. Hence, they are predominately used as hosts in the production of doped inorganic phosphors.…”

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles

“…A fast ramp rate tends to generate agglomerated NPs 33 , which affects their properties. In the case of luminescent and scintillation materials, high agglomeration is not desirable, as it can scatter excited and emitted light 17,19 . A slow ramp rate is thus more suitable and allows enough time to reach the actual temperature inside the crucible.…”

“…Generalizability: The MSS method is also a generalizable technique to produce nanoparticles with various compositions. Other than simple metal oxides and some fluorides, nanomaterials of complex metal oxides that have been successfully synthesized by the MSS method include perovskites (ABO 3 ) 10,11,12,13,14 , spinel (AB 2 O 4 ) 15,16 , pyrochlore (A 2 B 2 O 7 ) 4,17,18,19 , and orthorhombicstructures (A 2 B 4 O 9 ) 2,3,20 . More specifically, these nanomaterials include ferrites, titanates, niobates, mullite, aluminium borate, wollastonite, and carbonated apatite 7,9,21 .…”