Scheelite Structure Research Articles

Microwave dielectric properties of ternary molybdate NaSrLn(MoO4)3 (Ln = Nd, Sm) ceramics for LTCC applications

Two kinds of scheelite-structure microwave dielectric ceramics with I41/a space group were prepared by the conventional solid-phase reaction method. The effects of different sintering temperatures on the crystal structure, lattice vibration and microwave dielectric properties of NaSrLn(MoO4)3 (Ln = Nd, Sm) ceramics were investigated. XRD and Rietveld refinement results show that NaSrLn(MoO4)3 (Ln = Nd, Sm) ceramics belong to tetragonal scheelite structure with I41/a space group. The lattice vibration mode was analyzed by Raman spectroscopy, and the correlation between the dielectric performances and structure was established. The NaSrLn(MoO4)3 (Ln = Nd, Sm) ceramics have high density (>97%) and excellent microwave dielectric properties of εr = 10.47, Qf = 38951 GHz, τf = −48.43 ppm/°C for NaSrNd(MoO4)3 sintered at 775 °C and εr = 9.55, Qf = 41081 GHz, τf = −44.92 ppm/°C for NaSrSm(MoO4)3 sintered at 800 °C. In addition, NaSrLn(MoO4)3 (Ln = Nd, Sm) ceramics have excellent chemical compatibility with Ag electrodes, which means that the ceramic could be used in LTCC microwave devices.

Entropy regulation in LaNbO4-based fergusonite to implement high-temperature phase transition and promising dielectric properties

High-entropy effect is a novel design strategy to optimize properties and explore novel materials. In this work, (La_1/5Nd_1/5Sm_1/5Ho_1/5Y_1/5)NbO₄ (5RNO) high-entropy microwave dielectric ceramics were successfully prepared in the sintering temperature (S.T.) range of 1210–1290 ℃ via a solid-phase reaction route, and medium-entropy (La_1/3Nd_1/3Sm_1/3)NbO₄ and (La_1/4Nd_1/4Sm_1/4Ho_1/4)NbO₄ (3RNO and 4RNO) ceramics were compared. The effects of the entropy (<i>S</i>) on crystal structure, phase transition, and dielectric performance were evaluated. The entropy increase yields a significant increase in a phase transition temperature (from monoclinic fergusonite to tetragonal scheelite structure). Optimal microwave dielectric properties were achieved in the high-entropy ceramics (5RNO) at the sintering temperature of 1270 ℃ for 4 h with a relative density of 98.2% and microwave dielectric properties of dielectric permittirity (<i>ε</i>_r) = 19.48, quality factor (<i>Q</i>×<i>f</i>) = 47,770 GHz, and resonant frequency temperature coefficient (<i>τ</i>_f) = –13.50 ppm/℃. This work opens an avenue for the exploration of novel microwave dielectric material and property optimization via entropy engineering.

NaYW2O8: A novel glass-free microwave dielectric ceramic for LTCC application

Microwave dielectric ceramics are important materials for wireless communication devices because of their excellent dielectric properties. Tungstenate compounds with multiple scheelite structures can be used in low temperature co-fired ceramic (LTCC) devices because of their low densification temperature and high-quality factor. In this study, NaYW2O8 ceramics (NYW) were synthesized by a solid-state reaction method at a low densification temperature below the Ag melting point. The microstructure, morphology and microwave dielectric properties of NYW ceramics were investigated, and the effects of packing fraction and lattice energy on microwave dielectric properties were studied. The results showed that the microwave dielectric properties of NYW ceramics were influenced by the grain size and porosity, and deteriorated with the increase of porosity. In addition, the stacking fraction and lattice energy shared a similar trend with the quality factor. The NYW ceramics sintered at 925 °C exhibited excellent microwave dielectric properties with εr= 10.8, Q × f = 49,800 GHz (at 10.5 GHz), and τf= −26.5 ppm/°C. In particular, the NYW ceramics were found to have an excellent chemical compatibility with Ag. The above results indicate the NYW ceramics are candidate in LTCC applications.

Ultra-low lattice thermal conductivity in tungsten-based scheelite ceramics

BaWO4, Ce2/3□1/3WO4 and La2/3□1/3WO4 polycrystalline ceramics were synthesized by conventional solid-state reaction route. The effect of cation-deficiency on the crystallographic structure, microstructure and thermal properties of these scheelite-type compounds were investigated. X-ray diffraction was used to identify the single-phase scheelite structure of the studied ceramics. Scanning Electron Microscopy technique has revealed a homogenous and dense microstructure with a few micro-cracks. The thermal conductivity of BaWO4 scheelite decreases from 1.3 ± 0.2 to 1.0 ± 0.1 W m−1 K−1 in the range 373–673 K. The cation-deficient scheelites Ce2/3□1/3WO4 and La2/3□1/3WO4 ceramics display an ultra-low thermal conductivity of 0.3 ± 0.04 W m−1 K−1 and 0.2 ± 0.03 W m−1 K−1 at 673 K, respectively. These materials exhibit among the lowest known values of thermal conductivity in crystalline oxides, in this temperature range. Therefore, they appear as very attractive for thermal barrier coating and thermoelectric applications.

Microwave dielectric properties of glass free low temperature co-fired LixNa1−xY(MoO4)2(x = 0–0.4) ceramics with temperature stability

This study set out to the microwave dielectric properties of novel low temperature co-fired LixNa1−xY(MoO4)2(x = 0–0.4) ceramics and adjusted their temperature stability by doping Li+. The XRD confirmed that the doping in the range of x = 0–0.4 would not cause the emergence of the second phase, and the doped Li+ completely entered the lattice and formed LixNa1−xY(MoO4)2 solid solution ceramics, which had tetragonal scheelite structure. The εr and τƒ of LixNa1−xY(MoO4)2 ceramics move in a positive direction with the increase of doping amount, while the downward trend is observed in Q × ƒ. On the one hand, the change of εr and Q × ƒ at different sintering temperatures strongly depends on extrinsic factors such as density, grain size, and holes. On the other hand, this change is closely related to the ionicity, lattice energy, and packing fraction at different compositions. Besides, the change of τƒ can be attributed to the influence of bond valence. When x = 0, NaY(MoO4)2 ceramics have the highest Q × ƒ, and when x = 0.25, Li0.25Na0.75Y(MoO4)2 ceramics have the best temperature stability. Their properties are εr= 10.69, Q × ƒ= 53080.73 GHz, and τƒ= −46.84 ppm/°C and εr= 12.18, Q × ƒ= 30373.95 GHz, and τƒ= −6.35 ppm/°C, respectively. Normally, there is good compatibility between Li0.25Na0.75Y(MoO4)2 ceramics and Ag powders.

Photocatalytic Properties of PbMoO4 Nanocrystals against Cationic and Anionic Dyes in Several Experimental Conditions

This paper reports easy and fast synthesis of PbMoO4 nanocrystals by microwave-assisted hydrothermal (MH) method at different synthesis times (1, 10, 30 and 60 min) at 100 °C. X-ray diffraction, Rietveld refinement and Raman spectroscopy confirm all characteristics of diffraction peaks and active vibrational modes of the pure scheelite structure (tetragonal, I41/a) for all synthesized PbMoO4 nanocrystals. The optical bandgap calculated directly from the samples is close to 3.5 eV. The images collected by scanning electron microscopy show particles with mean length from 159.90(8) nm to 303.02(3) nm with greater exposure of planes (111), (100), (011) and (110). The photocatalytic activity of PbMoO4 nanocrystals against RhB and RBBR dyes resulted in successful degradation in short time intervals using ultraviolet light, where the best performance was achieved for the PbMoO4-10 sample, which was 29.2 and 51.8 times more effective than photolysis. The contribution of oxidant species was monitored by radical scavengers, which confirms that holes (h+) are the main oxidative species in photodegradation of RhB and RBBR dyes, while reuse of the catalyst against RhB and RBBR dyes confirms high stability of the catalyst, although recycled four times.

Microwave dielectric properties of tetragonal scheelite‐structured (NaY)1/2MoO4 ceramics

Abstract(NaY)1/2MoO4 was fabricated via the solid‐state reaction method of Na2CO3, Y2O3, and MoO3. Scanning electron microscopy results demonstrated that all the (NaY)1/2MoO4 ceramics could be densified well in the sintering temperature range of 900–960°C. Results of X‐ray diffraction analysis demonstrated that the (NaY)1/2MoO4 ceramics crystallized into tetragonal scheelite structure. Sintering (NaY)1/2MoO4 at 940°C for 2 h optimized the microwave dielectric properties of the ceramics. The microwave permittivity, Q × f, and TCF of the (NaY)1/2MoO4 were 10.9, 29 000 GHz and −40.7 ppm/°C, respectively.

High-Pressure Structural and Thermodynamic Properties of Cerium Orthosilicates (CeSiO4)

Pressure-induced phase transitions from the zircon structure-type (I41/amd) to the scheelite structure type (I41/a) are known for many ternary oxides systems (ABO4). In this work, we present the first high-pressure study on synthetic stetindite (CeSiO4) by a combination of in situ high-pressure synchrotron powder X-ray diffraction up to 36 GPa, implemented with and without dual sided laser heating, and in situ high-pressure Raman spectroscopy up to 43 GPa. Two phase transitions were identified: zircon to a high-pressure low-symmetry (HPLS) phase at 15 GPa and then to a scheelite at 18 GPa. The latter from HPLS scheelite phase was found irreversible; i.e., scheelite is fully quenchable at ambient conditions, as in other zircon-type phases. The bulk moduli (K0) of stetindite, HPLS, and high-pressure scheelite phases were determined, respectively, as 171(5), 105(4), and 221(40) GPa by fitting to a second-order Birch–Murnaghan equation of state. The pressure derivatives of vibrational modes and Grüneisen parameters of the zircon-structured polymorph are similar to those of other orthosilicate minerals. Due to the larger ionic radii of Ce4+, with respect to Zr4+, stetindite was found to possess a softer bulk modulus and undergo the phase transitions at a lower pressure than zircon (ZrSiO4), such observations are consistent with what were found in coffinite (USiO4).

Phase transitions and microwave dielectric behaviors of the (Bi1−xLi0.5xY0.5x)(V1−xMox)O4 ceramics

AbstractMicrowave dielectric ceramics with intrinsic low sintering temperatures are potential candidates for low temperature co‐fired ceramics technology. In the present work, the (Li0.5Y0.5)MoO4 ceramic with tetragonal scheelite structures was selected to improve microwave dielectric properties of BiVO4 ceramics. As proved by X‐ray diffraction (XRD) results, scheelite structured solid‐solution ceramics were formed with x value ≤0.1 in the (Bi1−xLi0.5xY0.5x)(V1−xMox)O4. In situ XRD results further confirmed that the addition of (Li0.5Y0.5)MoO4 also lowered transition temperature from distorted monoclinic to tetragonal scheelite structure. When x value increased further, zircon phase was detected by XRD. Room and high‐temperature Raman spectra also supported the XRD results. Differences of thermal expansion coefficients of both monoclinic and tetragonal scheelite phases lead to an abnormality at phase transition temperature. Good microwave dielectric properties with permittivity above 70 and Qf (Q = quality factor = 1/dielectric loss and f = frequency) value above 8000 GHz were obtained in the (Bi1−xLi0.5xY0.5x)(V1−xMox)O4 solid‐solution ceramics with x value ≤0.1 sintered below 800°C. However, permittivity peak values at phase transition temperatures lead to large positive or negative temperature coefficient of resonant frequency, and this needs to be modified via composite technologies in the future.

Synthesis and Luminescence Characteristics of CaWO4: Eu3+ Red Phosphor for White Light Emitting Diode

White light emitting diode (LED) red phosphor Ca1−xWO4:xEu3+ (x = 0.10, 0.15, 0.20, 0.25, 0.30) was prepared by high temperature solid state method. The phase of the phosphor sample was analyzed by X-ray diffraction (XRD) and the morphological characteristics of the sample were analyzed by scanning electron microscope (SEM), and the luminescence characteristics of the sample were studied by fluorescence spectrophotometer. The results show that the synthesized samples are scheelite structure and can be effectively excited by near ultraviolet light (393 nm) and blue light (464 nm). The main emission peak is located at 615 nm, which belongs to the 5D0→7F2 transition of Eu3+. The optimum doping amount of Ca1−xWO4:xEu3+ is 25%. In addition, Ca0.75WO4: Eu3+0.25 was prepared by sol–gel method, which was compared with the same component sample prepared by high-temperature solid-state method. It was found that the phosphor prepared by high-temperature solid-state method had relatively high luminous intensity.

Investigation of photocatalytic and luminescence properties of Na0.5Ce0.5WO4 self-assembled photocatalysts under solar light irradiation: Morphological, temperature and pH role

Tungstate-based scheelite structures have attracted much attention for the photocatalytic, adsorption and luminescence. To improve their performance, several ways have been considered, such as morphology control, thermal treatment and nanostructuring materials. In this work, three uniform and homogeneous morphologies, such as spindles, spheres and flowers, of self-assembled three-dimensional Na0.5Ce0.5WO4 were used as photocatalysts for methylene blue dye photodegradation under solar irradiation. Depending on morphology, they required different temperatures to reach crystallization. Thermal treatments at 500 °C and 800 °C resulted in changes in crystallite size, porosity, surface state, but also in bandgap and emission properties. Thus, the crystallite sizes are about 50 nm for samples (spindles and flowers) treated at 500°Cand 87–167 nm for those treated at 800 °C. Their respective bandgap values measured by diffuse reflectance were 2.85 eV beyond 3.15 eV. The samples treated at 500 °C showed a lower emission and a longer charge carrier lifetime. A strong trend to adsorption was revealed, especially at low pH value and for the samples treated at 500 °C, reaching 100% at a pH value of 2.5. With decreasing pH, the photocatalysis activity increases (up to 50%), being also more efficient with catalysts treated at low temperature. It follows that the degradation efficiency of spindles treated at 500 °C is clearly higher compared to other morphologies treated at different temperature, and suitable for solar photocatalysis.

Structural, Maorphological, Electrical and Optical Properties of SILAR Deposited Flowers Buds Like SrMoO4 Film

Successive Ionic Layer Adsorption and Reaction (SILAR) method is employed to deposit microcrystalline flowers buds like SrMoO4 film onto glass substrate using SrCl2 .6H2 O and Na2 MoO4 •2H2 O as cationic and anionic precursors respectively. Structural and morphological characterization of the film were carried out by means of X-ray diffraction, FTIR spectra, Field Emission Scanning Electron Microscopy and EDX studies, which confirms the formation of scheelite type tetragonal structure and flowers buds like microcrystalline grain growth of SrMoO4 film. The optical band gap and activation energy of the SrMoO4 film is found to be 3.6 and 1.15 eV respectively

Narrow-band dazzling red-emitting (LiCaLa(MoO4)3:Eu3+) phosphor with scheelite structure for hybrid white LEDs and LiCaLa(MoO4)3:Sm3+,Eu3+-based deep-red LEDs for plant growth applications.

Presently, the preparation of dazzling narrow-band red-emitting phosphors for solid-state lighting is still a challenge. In this context, herein, a series of pure narrow-band red-emitting LiCaLa1-xEux(MoO4)3 phosphors was synthesized and characterized, and their spectroscopic properties were systematically studied. In addition, a series of orange-red-emitting LiCaLa1-ySmy(MoO4)3 phosphors with the simultaneous doping of Eu3+ was synthesized for plant growth applications. The optical studies revealed that the phosphors showed pure red emission with a full width at half maximum of ∼5 nm and 97% color purity. Alternatively, their absorption spectrum showed good absorption strength in the near UV to blue region. Non-concentration quenching behavior was observed even when the concentration of Eu3+ in the lattice was 100%. The dominant electric dipole transition in the emission spectrum indicated that the Eu3+ ion occupies a non-centrosymmetric site in the lattice. At 150 °C, the phosphor retained 88.83% of its emission intensity calculated at room temperature. Thus, it can be useful for the fabrication of LEDs. Subsequently, Eu-rich red and white LEDs (integrated with yellow phosphor) were fabricated with near-UV and blue LED chips, respectively. The fabricated hybrid white LED showed pure white emission with a CCT of 4762 K, CRI of 81%, and close CIE coordinates of (0.34, 0.33). The absolute quantum yield for the fully substituted LiCaEu(MoO4)3 composition was calculated to be 44.50% upon excitation at 395 nm. To utilize LED light for plant growth applications, efforts were made to synthesize orange-red (Sm3+) and deep-red (Sm3+, Eu3+) phosphors and utilize the simultaneously doped phosphor for the fabrication of deep-red LEDs. The spectral lines well-matched the spectrum of phytochrome (Pr). Thus, the phosphor in the present study is a potential candidate as a red and deep-red phosphor for the fabrication of hybrid white LEDs and deep-red LEDs (for plant growth purposes), respectively.

Investigation of pyrochlore-type A2Sn2O7 (A = La, Nd, Sm, or Gd) ceramics as negative temperature coefficient thermistors for high-temperature application

This study puts forward a series of thermosensitive materials based on A2Sn2O7 (A = La, Nd, Sm, or Gd) ceramics for high-temperature applications. The A2Sn2O7 (A = La, Nd, Sm, or Gd) ceramics were synthesized following the solid-state route and characterized using techniques involving X-Ray diffraction, scanning electron microscopy, and Raman spectroscopy. It could be verified that the A2Sn2O7 (A = La, Nd, Sm, or Gd) ceramics had pyrochlore structures with relative densities ranging from 95.8 to 97.6%. The resistance-temperature measurements confirm that these ceramics have unique oxygen-insensitive negative temperature coefficient properties. The logarithm of resistivity depends on the reciprocal of temperature with excellent linearity over a wide temperature range of 400–1300 °C. A2Sn2O7 (A = La, Nd, Sm, or Gd) ceramics also exhibited well-ageing characteristics at their maximum upper applicable temperature of 1300 °C, in addition to the high resistivity and thermal constant B value that assured high accuracy. These properties outperformed those of the majority of high-temperature negative temperature coefficient ceramics based on scheelite or perovskite structures. The results suggested that the A2Sn2O7 (A = La, Nd, Sm, or Gd) ceramics could be potentially used for fabricating high-temperature NTC thermistors.

Bismuth Vanadate (BiVO4) Nanostructures: Eco-Friendly Synthesis and Their Photocatalytic Applications

Green nanotechnology plays an important role in designing environmentally-benign and sustainable synthesis techniques to provide safer products for human health and environments. In this context, the synthesis of bismuth vanadate (BiVO4) nanoparticles (NPs) based on green chemistry principles with the advantages of eco-friendliness, cost-effectiveness, and simplicity has been explored by researchers. Despite the advantages of these synthesis techniques, crucial aspects regarding their repeatability and large-scale production still need to be comprehensively explored. BiVO4 NPs have shown excellent potential in the pharmaceutical industry, cancer therapy, and photocatalysis. BiVO4 particles with monoclinic scheelite structures have been widely investigated for their environmental applications owing to their fascinating optical and electrical properties as well as their high stability and unique crystal structure properties. These NPs with good photostability and resistance to photocorrosion can be considered as promising nanophotocatalysts for degradation of pollutants including organic dyes and pharmaceutical wastes. However, additional explorations should be moved toward the optimization of reaction/synthesis conditions and associated photocatalytic mechanisms. Herein, recent developments regarding the environmentally-benign fabrication of BiVO4 NPs and their photocatalytic degradation of pollutants are deliberated, with a focus on challenges and future directions.

Design and Fabrication of a C-Band Dielectric Resonator Antenna with Novel Temperature-Stable Ce(Nb1-xVx)NbO4 (x = 0-0.4) Microwave Ceramics.

Vanadium(V)-substituted cerium niobate [Ce(Nb1-xVx)O4, CNVx] ceramics were prepared to explore their structure-microwave (MW) property relations and application in C-band dielectric resonator antennas (DRAs). X-ray diffraction and Raman spectroscopy revealed that CNVx (0.0 ≤ x ≤ 0.4) ceramics exhibited a ferroelastic phase transition at a critical content of V (xc = 0.3) from a monoclinic fergusonite structure to a tetragonal scheelite structure (TF-S), which decreased in temperature as a function of x according to thermal expansion analysis. Optimum microwave dielectric performance was obtained for CNV0.3 with permittivity (εr) of ∼16.81, microwave quality factor (Qf) of ∼41 300 GHz (at ∼8.7 GHz), and temperature coefficient of the resonant frequency (TCF) of ∼ -3.5 ppm/°C. εr is dominated by Ce-O phonon absorption in the microwave band; Qf is mainly determined by the porosity, grain size, and proximity of TF-S; and TCF is controlled by the structural distortions associated with TF-S. Terahertz (THz) (0.20-2.00 THz, εr ∼ 12.52 ± 0.70, and tan δ ∼ 0.39 ± 0.17) and infrared measurements are consistent, demonstrating that CNVx (0.0 ≤ x ≤ 0.4) ceramics are effective in the sub-millimeter as well as MW regime. A cylindrical DRA prototype antenna fabricated from CNV0.3 resonated at 7.02 GHz (|S11| = -28.8 dB), matching simulations, with >90% radiation efficiency and 3.34-5.93 dB gain.

Novel double molybdate LiLu(MoO4)2:Sm3+ red phosphors with excellent thermal stability for white LEDs

A series of LiLu(MoO4)2:Sm3+ red phosphors with high thermal stability were synthesized by sol-gel method. The crystal structure, morphology, concentration-dependent luminescence spectra and temperature-dependent luminescence spectra/decay times of the phosphors were systematically investigated. The LiLu(MoO4)2:Sm3+ phosphors have a scheelite structure with tetragonal system. Under the UV excitation of 405 nm, the LiLu(MoO4)2:Sm3+ phosphors emit red light centered at 648 nm corresponding to the 4G5/2→6H9/2 transition of the Sm3+ ion. LiLu(MoO4)2:Sm3+ red phosphors exhibited high color purity (98.84%) and a CIE coordinate (0.5806, 0.4145). The LiLu(MoO4)2:Sm3+ phosphors also demonstrate an excellent luminescence thermal stability (the luminescence intensity at 473 K remains 93% of that at 298 K). These experimental results demonstrate the potential application of LiLu(MoO4)2:Sm3+ phosphor in the red component of white light-emitting diodes.

Defect assisted enhanced nonlinear optical performance and optical limiting of pure and doped BiVO4 powders and nanocomposite films

The linear and nonlinear absorption properties, photoluminescence and optical limiting properties of bismuth vanadate (BiVO4) powders and films were presented in this work. The structural, morphological and optical effects of different doping elements (M: Mo,W and Ni) were investigated (M: BiVO4). XRD and Raman results proved that BiVO4 and M: BiVO4 powders were synthesized in the monoclinic scheelite structure. Twhe powder morphology as found to be changed by Ni and W doping. The nonlinear optical responses of pure and M: BiVO4 were studied using the open aperture Z-scan experiment and a theoretical model was used to determine the nonlinear optical absorption performance. The nonlinear absorption coefficient (βeff) values were found to be 6.59 × 104, 8.86 × 104, 2.26 × 105 and 1.62 × 106 cm/GW for BiVO4, Mo: BiVO4, W: BiVO4 and Ni: BiVO4 nanocomposite films, respectively. The highest nonlinear absorption coefficients (βeff) and saturation intensity thresholds (ISAT) were obtained for Ni:BiVO4 film. Experimental results showed that the βeff value and band gap can be controlled by the dopant element, making doped BiVO4 a good candidate for nonlinear optical applications such as optical limiters, optical switches and modulators in integrated photonic devices.

Tetrahedral Displacive Disorder in the Scheelite-Type Oxide RbReO4.

Oxides exhibiting the scheelite-type structure are an important class of functional materials with notable applications in photocatalysis, luminescence, and ionic conductivity. Like all materials, understanding their atomic structure is fundamental to engineering their physical properties. This study outlines a detailed structural investigation of the scheelite-type oxide RbReO4, which exhibits a rare long-range phase transition from I41/a to I41/amd upon heating. Additionally, in the long-range I41/a model, the Re-O tetrahedral distance undergoes significant contraction upon warming. Recent studies of other scheelite oxides have attributed this apparent contraction to incoherent local-scale tetrahedral rotations. In this study, we use X-ray pair distribution function analysis to show that RbReO4 undergoes a unique symmetry-lowering process on the local scale, which involves incoherent tetrahedral displacements. The rare I41/a to I41/amd long-range phase transition was found to occur via a change from static to dynamic disorder on the local scale, which is due to the combination of the size of the A-site cation and lattice expansion. This demonstrates how careful manipulation of the ionic radius of the A-site in the scheelite structure can be used to induce local-scale disorder, which has valuable implications for tailoring the physical properties of related materials.

A novel highly thermal-stable red-emitting CaGdSbWO8:Eu3+ phosphor with scheelite structure for high CRI w-LEDs,security ink, and latent fingerprint

Recently, rare-earth doped phosphors have been newly developed and applied in hot issues such as phosphor-converted light-emitting diodes (pc-LEDs), anti-counterfeiting, and fingerprint visualization. Herein, an Eu 3+ -activated CaGdSbWO 8 (CGSW) red phosphor was synthesized by a high-temperature solid-state reaction. The phosphors can exhibit narrow red-light emission at 614 nm due to the electric dipole transition 5 D 0 → 7 F 2 of Eu 3+ . Impressively, this phosphor has excellent thermal stability, its emission intensity of optimum sample doped with 0.30 Eu 3+ remained 90.61% at 420 K and thermal quenching temperature exceeds 480 K. The Commission International del’Eclairage (CIE) chromaticity coordinates of CGSW:0.30Eu 3+ are (0.662, 0.338) with a high color purity (98.5%). The fabricated white light diode (w-LED) has a high color rendering index (91.4) and a low correlated color temperature (4986 K) with CIE coordinates (0.343, 0.327). Further experimental results showed that the prepared security ink can be applied to anti-counterfeit labels and information encryption. The latent fingerprint developed by CGSW:0.30Eu 3+ phosphor present the excellent selectivity and contrast. The level 1–3 structural characteristics of latent fingerprints could be well identified under ultraviolet irradiation. Therefore, the Eu 3+ -activated CGSW red-emitting phosphor has broad application prospects due to its excellent luminescence properties. • Novel CaGdSbWO 8 :Eu 3+ phosphors have been synthesized via high-temperature solid-state method. • The CaGdSbWO 8 :Eu 3+ phosphors with scheelite structure have good thermal stability ( T 0.5 >480 K). • The w-LED fabricated by the phosphor exhibits a high CRI value of 91.4 and a good CCT of 4986 K. • The applications in security ink and latent fingerprint of CaGdSbWO 8 :Eu 3+ phosphors are investigated in details.