RE Ions Research Articles

In situ dopant-induced nano-crystallization of rare-earth-fluoride crystals in phase-separated networks for highly-efficient photoemission and photonic devices

RE-fluoride nanocrystals are controllably precipitated in glass by in situ dopant-induced crystallization strategy. RE ions spontaneously enter fluoride crystals, greatly enhancing the luminescence efficiency as compared to traditional materials.

Selective Permeation of Neodymium Through an Alloy Diaphragm in Molten Chloride Systems

The authors have been investigating a new RE (RE=Dy and Nd) recycling process from Nd-Fe-B permanent magnets, which is characterized by the use of RE-IG (IG=Fe, Ni, Co) alloy diaphragms for separation of REs in molten salts (Fig. 1) [1, 2]. In this process, the RE-IG alloy diaphragm performs as a bipolar electrode and RE ions permeate via three steps: (1) reduction of RE ions to form alloy on the anolyte side of the diaphragm, (2) diffusion of RE atoms in the diaphragm, and (3) oxidation of RE atoms to dissolve into the catholyte as RE ions on the other side of the diaphragm. Because the reaction and diffusion rates depend on the kinds of RE elements and the electrolytic conditions, selective permeation of Dy and/or Nd is possible under an appropriate condition. Using this selective permeation phenomenon through the alloy diaphragms, Dy and Nd can be separately recovered from Nd-Fe-B permanent magnets only by molten salt electrolysis, as shown in Fig. 1.Recently, the authors reported selective Dy permeation through a RE-Ni alloy diaphragm in molten LiCl-KCl eutectic melts containing NdCl3 and DyCl3 at 450 ℃ [3]. Whereas, in the present study, selective permeation of Nd was examined using a similar experimental setup at the different electrolytic conditions. The obtained molar ratio of permeated Nd/Dy was around 6. Interestingly, EDX analysis revealed that the molar ratio of Nd/Dy in the alloy diaphragm was less than 0.05, which was two orders of magnitude lower than that of the permeated amount. These results suggested that the diffusion rate of Nd atoms in the alloy diaphragm was extremely high compared to that of Dy.AcknowledgementThis work was partly supported by the New Energy and Industrial Technology Development Organization (NEDO) of Japan.Reference[1] T. Oishi, H. Konishi, T. Nohira, M. Tanaka and T Usui, Kagaku Kogaku Ronbunshu, 36, 299–303 (2010).[2] T. Oishi, Molten Salts (Yoyuen Oyobi Koon Kagaku), 63, 78–83 (2020).[3] T. Oishi, M. Yaguchi, Y. Katasho and T. Nohira, Rare metal technology 2020, 151–156 (2020). Figure 1

An O- modified coordination polymer for rapid and selective adsorption of rare earth elements from aqueous solution

In this work, a novel porous coordination polymer (CP) modified by O− groups is synthesized, which exhibits superior adsorption capacity for RE ions (211 mg g-1 for Gd3+, 183 mg g-1 for Pr3+ and 179 mg g-1 for Sm3+). Moreover, RE ions adsorption show a rapid process, especially, at an initial RE ions concentration of 1 ppm, the time to reach equilibrium was as short as 10 min. The high adsorption affinity make the adsorbent not only shows efficient adsorption of lower concentration RE3+ (1 ppm), but also exhibits excellent selectivity in the presence of competitive ions. Besides, the removal rate of RE3+ is more than 99 % in column chromatography separation using the CPs as fillers. The isothermal adsorption results are well described by the Langmuir model, and the adsorption kinetics fits well with pseudo-second-order kinetic model. Zeta potential, FT-IR and XPS demonstrate that electrostatic interactions and coordination reaction between O− groups and RE3+ are mainly adsorption mechanism. As far as we know, ordinary CP material exhibiting fast and efficient adsorption behavior for low concentration REEs is still rarely reported.

Evolution of two bulk-superconducting phases in Sr0.5RE0.5FBiS2 (RE: La, Ce, Pr, Nd, Sm) by external hydrostatic pressure effect

Polycrystalline samples of Sr0.5RE0.5FBiS2 (RE: La, Ce, Pr, Nd, and Sm) were synthesized via the solid-state reaction and characterized using synchrotron X-ray diffraction. Although all the Sr0.5RE0.5FBiS2 samples exhibited superconductivity at transition temperatures (Tc) within the range of 2.1–2.7 K under ambient pressure, the estimated superconducting volume fraction was small, which indicates non-bulk nature of superconductivity in those samples under ambient pressure. A dramatic increase in shielding fraction, which indicates the emergence of the bulk superconductivity was achieved by applying external hydrostatic pressures. We found that two phases, low-P phases with Tc = 2.5–2.8 K and high-P phases with Tc = 10.0–10.8 K, were induced by the pressure effect for samples with RE = La, Ce, Pr, and Nd. Pressure-Tc phase diagrams indicated that the critical pressure for the emergence of the high-P phase tends to increase with decreasing ionic radius of the doped RE ions, which was explained by the correlation between external and chemical pressure effects. According to the high-pressure X-ray diffraction measurements of Sr0.5La0.5FBiS2, a structural phase transition from tetragonal to monoclinic also occurred at approximately 1.1 GPa. Bulk superconducting phases in Sr0.5RE0.5FBiS2 induced by the external hydrostatic pressure effect are expected to be useful for understanding the effects of both external and chemical pressures to the emergence of bulk superconductivity and pairing mechanisms in BiCh2-based superconductors.

Comparative study of CSD-grown REBCO films with different rare earth elements: processing windows and Tc

REBa2Cu3O7−x (REBCO, RE = rare earth) compounds with different single RE elements were grown via TFA-MOD (metal-organic deposition of trifluoroacetates) to clarify their Tc values when grown by the same preparation method and their processing windows; here: the crystallisation temperatures at a constant process gas composition (pO2, pH2O). We focussed on the lanthanides (Ln) Nd, Sm, Gd, Dy, Ho, Er and Yb as substituents for Y in the REBCO phase and investigated their growth behaviour in terms of resulting physical (inductive Tc and Jc(77 K)) and structural properties (determined by XRD, SEM, TEM). All phases were grown as pristine films on LaAlO3 and SrTiO3 and compared to their respective nanocomposites with 12 mol% BaHfO3 for in-field pinning enhancement.With regard to Tc and Jc(77 K), the optima of both values shift towards higher growth temperatures for increasing and decreasing RE ion size with respect to yttrium. Highest Tc values achieved so far do not show a trend that can solely be related to the RE ionic size. On the contrary, Tc,90 values of the LnBCO compounds from Sm to Er range between 94.0 and 95.3 K and are, therefore, significantly larger than the highest values of the average-size non-lanthanide, Y, with Tc,90 = 91.5 K. Jc,sf values at 77 K seem to plateau between 5 and 6 MA cm−2 from Sm to Er and are again clearly above the maximum values we ever achieved for Y with 4.2 MA cm−2. REBCO phase formations of the very small Yb and large Nd turned out to be more difficult and require further adjustment of growth parameters. All REBCO phases investigated here show distinct dependences of Tc on the lattice parameter c.

Diversity of Local Environments of RE Ions in Aluminoborosilicate Glasses

Luminescence and excitation spectra are analyzed along with the kinetics of luminescence decay for aluminoborosilicate glasses containing rare earth (Sm, Eu and Ce) oxides. It is found that the measured spectra depend on the moment of experimental registration, the wavelength of excitation, and the concentration of rare earth activators. Variations in spectra are associated with differences in the local environment of the rare earth activator.

The effect of Sn doping on the optical properties and thermal stability of rare-earths-doped Na3Gd(VO4)2 double vanadate materials

The Sn single doped and Sn/rare-earth (RE) ions (Eu3+, Dy3+, and Sm3+) co-doped Na3Gd(VO4)2 (NGVO) materials were synthesized using a sol-gel method by mixing stoichiometric amounts of the precursors. All the samples gave intense diffraction peaks without any shift in the 2θ values and did not show any impurity phases. The scanning electron microscope images of Sn and RE ions co-doped samples did not show significant changes with the dopant ions, and the elements present in the samples was analyzed with energy dispersive X-ray spectrometry. Introducing Sn into the V site showed enhanced optical characteristics due to the formation of oxygen vacancies and lattice distortions in the host lattice. Similarly, when the NGVO host was co-doped with Sn and RE ions, the optical properties of the RE were enhanced. Temperature-dependent optical properties of the Sn co-doped NGVO: RE samples were also fortified due to the Sn co-doping and showed an increase in thermal activation energy values when compared with NGVO: RE samples.

A review on rare earth (Ce and Er)-doped zinc oxide nanostructures

Diverse nanostructures of ZnO are one of the most studied materials. ZnO nanostructures possess several favourable properties such as good transparency, strong room-temperature luminescence, high electron mobility, wide band gap, chemical and photochemical stability, etc. These properties make them an interesting material for using in new light-emitting devices, solar cells, bio-sensors and as photocatalysts. They are generally of very low toxicity. ZnO nanostructures are an emerging material for next-generation. Doping is considered an effective way to enhance the properties of ZnO for various applications. In this framework, the doping of RE ion in ZnO is of great importance due to signs of tuneable luminescence and ferromagnetism at room temperature. RE ions are extensively used as activators in different host materials due to their high fluorescence efficiencies and very narrow line fluorescence bands. The ferromagnetism property of RE doped ZnO nanostructures is another such property which has drawn a great interest. These nanostructures find applications in magneto-optical device applications i.e. communications, storage, quantum computation etc. This review provides an overall study of the synthesis of Ce and Er doped ZnO nanostructures from various methods, and their properties and applications in different fields of industry.

Multicolour tuning of different RE ion doped CaMoO4 nanoparticles by single wavelength excitation

A novel Li+ co-doped RE doped CaMoO4 nanospheres were synthesized adopting polyol technique under urea hydrolysis method. XRD confirms that all the ensued particles are crystallized in the scheelite type tetragonal phase. Transmission electron microscopy observation confirms the formation of small spherical undoped and 5 at % Eu3+, Sm3+ and Dy3+ doped CaMoO4 NPs with a narrow particle size distribution and an average particles diameter of 10.64, 7.18, 3.77 and 3.62 nm, respectively. An increase in the emission intensity with the incorporation of Li ion in the host lattice was discussed in detail. It was found that Li+ ion act as a charge compensator or sensitizer for decreasing emission intensity ratios of MoO42− group to the activator ions. Our work may provide an alternative pathway for tailoring nanocrystals with enhanced optical properties, paving the way for their utilities in the commercialization in optical display systems, lasers and optoelectronic devices.

Role of silver/titania nanoparticles on optical features of Sm3+ doped sulfophosphate glass

This study reports the impact of silver (Ag)/titania (TiO2) nanoparticles (TNPs) on optical and photocatalytic features of samarium ions (Sm3+) doped sulfophosphate glass system. Sulfophosphate glasses with the molar composition of (58.5-x) P2O5-20.0MgO-20.0ZnSO4-1.0Sm2O3-0.5Ag-xTiO2 with x = 0.0, 0.1, 0.2, 0.3 and 0.4 mol% were synthesized. Density and molar volume have been measured and calculated. TEM image revealed the contribution of both Ag NPs and TiO2 NPs in the glass samples. Surface plasmon resonance (SPR) peaks of Ag positioned at 560 and 585 nm as well as SPR peaks around 407 and 847 nm for TNPs. There were three prominent peaks in emission spectra which centered at around 562, 598 and 643 nm. PMZSA0.1Ti glass sample revealed the highest value of PL intensity, which was assigned to the localized surface plasmon resonance (LSPR) of Ag/TiO2 nanoparticles and noticeable enhancement in the field effects around the RE ions. The radiative properties of the proposed samples were studied via the Judd-Ofelt (J-O) analysis. The results of the surface hydrophilicity and the photocatalytic activity of the samples in the existence of Ag/TiO2 NPs confirm the self-cleanness characteristics of the presented glasses.

The features of Pr3+ rare-earth ion magneto-optics in the disordered crystalline surroundings

The photoluminescence excitation (PLE) and photoluinescence spectra of the La3Ga5SiO14:Pr3+ single crystal were measured in the spectral ranges of 225–300 and 478–510 nm, respectively, by the VUV spectroscopy at T = 80 K. The absorption band frequency with prima facie form of the wide structureless band and associated with allowed 4f2(3H4) → 4f(1)5d transition in Pr3+ ions was determined on the basis of the spectral studies of the PLE of the La3Ga5SiO14:Pr3+ crystal. Moreover, the disorder in the crystal surroundings of the rare-earth Pr3+ ion in these compounds leads both to the broadening of the observed 3H4 → 3P0,1,2 absorption lines and their strong mutual overlapping in the wavelength range of 400–500 nm. Therefore, the detailed consideration of the crystalline surroundings disorder influence on the RE ions magnetooptics makes it possible to carry out a simplified theoretical consideration of the Pr3+ ion magnetooptical activity (MOA) features in the trigonal Ca-gallogermanate Сa3Ga2Ge4O14:Pr3+ and langasite La3Ga5SiO14:Pr3+ crystals. A spectral dependence of the magnetic circular dichroism (MCD) in the Ca3Ga2Ge4O14:Pr3+ was measured at the temperatures 90 and 300 K in the region of 400–500 nm. From the results of the magnetooptical experiment the ratio of the Judd parameters of the intensity for the transitions Ω6:Ω4 was found. In addition, the experimental determination and theoretical estimation of MOA factor C/D for MCD bands at the 450 and 475 nm were carried out.

Li8CaRE2Ta2O13 (RE=La3+, Eu3+, Gd3+, Dy3+, Er3+, Y3+, Yb3+): A highly lithium-stuffed tantalate garnet with versatile luminescence characteristics

Highly lithium-stuffed tantalates Li8CaRE2Ta2O13 (RE = La3+, Eu3+, Gd3+, Dy, Er3+, Y3+, Yb3+) were prepared by incorporating Ca2+ ions in the lattices of the well-known garnet Li5La3Ta2O12. The well-crystallized ceramic samples were synthesized via high-temperature solid-state reaction. Rietveld structural refinements were applied to verify the phase formations. The detailed luminescence properties of these rare-earth ions (RE)-concentrated tantalates were investigated. The phosphors show versatile luminescence phenomena without concentration quenching due to the Ca2+ ions incorporation. Under excitation with UV radiation, the luminescence band peaking at 435 nm was detected in Li8CaRE2Ta2O13 (RE = La3+, Gd3+, Y3+, Yb3+) even at room temperature, which is from the electronic transitions of self-activation centers. Especially, Li8CaRE2Ta2O13 (RE = La3+) shows scintillating characteristics under X-ray irradiation. In Li8CaRE2Ta2O13 (RE = Eu3+, Dy3+, Er3+, Yb3+), UV-excitations produce characteristic f-f transitions of RE ions caused by energy transfers from TaO6 centers. Li8CaRE2Ta2O13 (RE = Eu3+) presents the strong red emission under both near-UV and blue excitation, which shows potential phosphor for fabrications of white LEDs. The experimental lamps were fabricated by packaging the prepared phosphors with near-UV LED-chips. The intense green upconversion is observed in Li8CaRE2Ta2O13 (RE = Er3+) under near-IR excitation at 980 nm. The luminescence mechanism was investigated via applying the site-selective excitation and emission of the spectral probe Eu3+ ions and discussed on basis of the structural characteristic.

Fabrication and characterization of rare earth (Ce, Gd, and Y) doped ZrO2 based metal-insulator-semiconductor (MIS) type Schottky barrier diodes

The 8 wt% rare earth (RE = Ce, Gd, and Y) doped zirconium dioxide (ZrO2) thin films were prepared on glass substrates by spin-coating technique and annealed at 600 °C. Also, the RE:ZrO2 based metal-insulator-semiconductor (MIS) type Schottky barrier diodes were fabricated. X-ray diffraction (XRD) patterns revealed the mixed phase of monoclinic and tetragonal ZrO2 for the RE:ZrO2 films, and the pure monoclinic phase for the undoped ZrO2 film. Because of the doping with RE ions, the crystallite size reduced with the increase of oxygen vacancies. The scanning electron microscopic (SEM) images exhibited the rod-shaped and square-shaped grains for the undoped ZrO2 and Gd:ZrO2 thin films, respectively. Elemental compositions were confirmed by the energy dispersive X-ray (EDX) analysis. The UV–vis analysis showed the lower transmittance for the RE:ZrO2 films with a reduced band gap (Eg). The dc electrical conductivity (σdc) was increased with the decrease of activation energy (Ea) due to the RE doping. When compared to the Al/undoped ZrO2/p-Si Schottky barrier diode, the Al/RE:ZrO2/p-Si showed an improvement in the values of barrier height (ΦB), ideality factor (n), and series resistance (RS).

Water dispersible ligand-free rare earth fluoride nanoparticles: water transfer versus NaREF4-to-REF3 phase transformation.

The chemical stability of oleate-capped sub-10 nm α- and β-NaREF4 NPs (RE = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu for α- and RE = Pr, Nd, Sm, Eu, Gd, Tb, Dy for β-phase NPs) was evaluated under the acidic conditions used for ligand removal towards water dispersibility. It was found that for such small NPs, a pH lower than 3 was necessary for the water transfer to be efficient and to yield well-dispersed ligand-free NPs. In stark contrast to the generally considered good chemical stability of NaREF4, these conditions were observed to pose a risk to phase transformation of the NaREF4 NPs into much larger, hexagonal- or orthorhombic-phase REF3, depending on the NP composition. A correlation between the thermodynamic stability of the α/β-NaREF4 and the hexagonal/orthorhombic REF3 phases - dictated by the RE ion choice - and the chemical stability of the NPs was found. For instance, β-NaGdF4 NPs remained stable, while α-NaGdF4 NPs underwent phase transformation into hexagonal GdF3. More general, NaREF4 NPs based on lighter RE ions were more prone towards phase transformation, while those based on heavier RE ions exhibited stability. Herein, within the RE series, the borderline for phase transformation was identified as Tb/Dy for α-NaREF4 NPs and Sm/Eu for β-NaREF4 NPs, respectively. Also, given the large interest in luminescent NPs for, e.g. biomedical applications, optically active Ln3+ ions (Ln = Nd, Eu, Tb, Er/Yb) were doped into α/β-NaGdF4 host NPs, and the dopant influence on the chemical stability was evaluated. Steady state and time-resolved spectroscopy unveiled spectral features characteristic for Ln3+ f-f transitions, i.e. downshifting and upconversion, before and after ligand removal. Overall, the results herein described emphasise the importance of minding the chemical procedure used for ligand removal of NaREF4 NPs of different crystalline phases and RE compositions.

Blackbody emission from CaF2 and ZrO2 nanosized dielectric particles doped with Er3+ ions.

We studied the features of the appearance of broadband “white” emission in CaF2-x mol% ErF3 and ZrO2-x mol% Er2O3 (x = 0–25) nanosized dielectric particles upon their excitation by intense laser radiation with λexc = 1550 nm. Comparison of the results of this study with the results obtained previously for other materials doped with Er3+ ions confirmed the thermal nature of the observed emission and made it possible to identify the main factors affecting its occurrence. These include the band gap of the material and the presence of defects in its structure. A method of applying the effect in dermatology is proposed.

Effect of Gd2O3 on luminescence properties of RE ions in germanium-tellurite glasses

The system of Ho3+/Yb3+ co-doped Ge-Te-Ga-Gd glasses has been successfully prepared by traditional melting method. The thermal stability, Raman spectroscopy and mid-infrared luminescence were studied and analyzed systematically. The effectively enhanced thermal stability of the sample was obtained with the increasing introduced Gd2O3, which was confirmed by the positive ΔT values. The improved robustness and structural stability of the glass network were analyzed through Raman spectroscopy. Enhanced 2–3 μm emissions have been obtained by certain content Gd2O3 with an optimal choice of 15 mol% additive amount under 980 nm pumping. Furthermore, luminous parameters including J-O values, absorption, emission and gain cross sections have been presented together with energy transfer mechanism. Hence, this paper presents a new choice of Ho3+/Yb3+ co-doped Ge-Te-Ga-Gd glass as potential mid-infrared laser materials.

A new eulytite-type Pb3Bi(PO4)3:Eu3+ red-emitting phosphor: Synthesis, structure and photoluminescence characteristics

Exploring new luminescent host is important for spectral regulation purpose in this field since photoluminescent characteristics of RE ions are highly sensitive to the doping host. Herein, a new eulytite-type Pb3Bi(PO4)3:Eu3+ phosphor was synthesized via high temperature solid state reaction, and structure, luminescence properties and thermal stability were studied. It is known from XRD that the phosphor has a body-centered cubic structure and belongs to the I4‾3d(220) space group. In this structure, one crystallographic site is mixed occupied by Pb and Bi atoms at the molar ratio of 3:1. In the effective excitation at 394 nm, all Pb3Bi(PO4)3:Eu3+ phosphors emitted bright red light and the color coordinates located at red region. Concentration quenching was not observed in the Eu3+ doping concentration within 10 mol%, and the fluorescence lifetime almost unchanged with the increase of doping concentration, indicating the host has a high quenching concentration. When the temperature is raised by 150 K, the emission intensity of the phosphor still retains 40% of the original intensity, and the activation energy Ea = 0.245 eV, indicating that the thermal stability of the phosphor is good. The above results demonstrated that the Pb3Bi(PO4)3:Eu3+ phosphors are very promising for use in blue and near-ultraviolet light excited w-LEDs.

Reactive Element Effects in High-Temperature Alloys Disentangled

Reactive elements—REs—are decisive for the longevity of high-temperature alloys. This work joins several previous efforts to disentangle various RE effects in order to explain apparently contradicting experimental observations in alumina forming alloys. At 800–1000 °C, “messy” aluminum oxy-hydroxy-hydride transients initially formed due to oxidation by H2O which in turn undergo secondary oxidation by O2. The formation of the transient oxide becomes supported by dispersed RE oxide particles acting as water equivalents. At higher temperatures, electron conductivity in impurity states owing to oxygen vacancies in grain boundaries (GBs) becomes increasingly relevant. These channels are subsequently closed by REs pinning the said vacancies. The universality of the emerging understanding is supported by a comparative first-principles study by means of density functional theory addressing RE(III): Sc2O3, Y2O3, and La2O3, and RE(IV): TiO2, ZrO2, and HfO2, that upon reaction with water, co-decorate a generic GB model by hydroxide and RE ions. At 100% RE coverage, the GB model becomes relevant at both temperature regimes. Based on reaction enthalpy ΔHr considerations, “messy” aluminum oxy-hydroxy-hydride transients are accessed in both classes. Larger variations in ΔHr are found for RE(III)-decorated alumina GBs as compared to RE(IV). For RE(III), correlation with GB width is found, increasing with increased ionic radius. Similarly, upon varying RE(IV), minor changes in stability correlate with minor structural variations. GB decorations by Ce(III) and Ce(IV) further consolidate the emerging understanding. The findings are used to discuss experimental observations that include impact of co-doping by RE(III) and RE(IV).

Color tunability and white light generation through up-conversion energy transfer in Yb3+ sensitized Ho3+/Tm3+ doped tellurite glasses

In this study, tellurite glasses in the (50-x)TeO2-25WO3-25Li2O-xRE (RE: Ho3+, Tm3+, Yb3+) system were synthesized to investigate white light generation through up-conversion energy transfer. Thermal properties of glasses were studied, and optical absorption spectra were collected. Energy transfer mechanisms between RE ions and effect of RE concentrations on up-conversion emission and color tunability were investigated through photoluminescence analysis under 980 nm excitation. Additionally, effect of excitation power on up-conversion emission intensities were investigated. Colorimetric properties such as CIE color coordinates, correlated color temperature, color rendering index and color purity were calculated. The obtained colorimetric results under 2 watt pump power were comparable or better than other reported glass systems. H005T025Y2 sample was found to show the closest color coordinates (x = 0.32 and y = 0.33) to pure white light and suitable colorimetric properties indicating that studied glasses have high potentiality to be used as luminescent materials for white light generation.

Ratiometric and colorimetric fluorescence temperature sensing properties of trivalent europium or samarium doped self-activated vanadate dual emitting phosphors

Herein, a new optical thermometry scheme based on the differences in thermal quenching behavior between self-activated [VO4]3- groups and rare earth doped ions is proposed by using fluorescence intensity ratio (FIR) technique. We successfully synthesized self-activated, Eu3+-, and Sm3+-activated singe-phase Ca2NaMg2V3O12 phosphors. The luminescence and temperature sensing properties of host, Ca2NaMg2V3O12:Eu3+ and Ca2NaMg2V3O12:Sm3+ were systematically investigated. By analyzing luminescence spectra, we find that Ca2NaMg2V3O12 exhibits a green broadband emission under 335 nm UV excitation, while Sm3+- and Eu3+-doped Ca2NaMg2V3O12 phosphors show one green broadband emission and some sharp lines, which originate from the CT between V5+ and O2− of [VO4]3- group and RE ions 4f–4f transition. Tunable color emission has been obtained by changing the contents of Eu3+ and Sm3+. With an increasing of the temperature, the fluorescence intensity of [VO4]3- dramatically reduce while that of Eu3+ and Sm3+ slightly decline owing to the different quenching activation energy, which is 0.494 eV, 0.510 eV and 0.587 eV, respectively. Especially, Originated from the different thermal response, the FIR of Eu3+ and Sm3+ to [VO4]3- show an amazing temperature sensing properties. The maximum relative sensitivity of Ca2NaMg2V3O12:Eu3+ and Ca2NaMg2V3O12:Sm3+ is 1.686% K−1 (443 K) and 1.889% K−1(463 K), respectively, which is much higher than most reported optical thermometry materials. The emitting color of Ca2NaMg2V3O12:Eu3+ was tune from green to reddish-orange in the range of 303 K–503 K while that of Ca2NaMg2V3O12:Sm3+ from green to orange. The experimental results indicated that the obtained phosphors may have potential applications in ratiometric and colorimetric temperature sensing.