Sodium Bismuth Titanate Research Articles

Effect of composition induced transition in the optical band-gap, dielectric and magnetic properties of Gd doped [formula omitted] complex perovskite

The optical band-gap, dielectric and magnetic properties of gadolinium doped sodium bismuth titanate ceramics, Na0.5Bi0.5−xGdxTiO3 (NBT:xGd) with x=0,0.005,0.01,0.015and0.02, sintered by the conventional solid-state reaction were studied at room temperature. The X-ray diffraction (XRD) patterns revealed that the doping with Gd3+ ions into the ceramics resulted in rhombohedrally distorted perovskite structure. The microstructure morphology observed through the Scanning Electron Microscopy (SEM) are generally submicron level with the presence of micro-pores close to the grain boundary regions. It was found that band-gap energy values, Eg decreased with Gd-doping, being 3.247 and 3.151 eV for x=0 and 0.02, respectively. The dielectric properties of NBT:xGd samples were predominantly due to the interfacial effects at lower frequencies due to the presence of oxygen vacancies. Further, the long-range interaction between the Gd3+ ions changed the diamagnetic behavior in NBT samples to paramagnetic in the NBT:xGd ceramics.

Ultrahigh energy density and improved discharged efficiency in bismuth sodium titanate based relaxor ferroelectrics with A-site vacancy

Novel A-site deficient (1-x-y)Bi0.5Na0.5TiO3-xBaTiO3-yBi0.2Sr0.7TiO3 lead-free relaxor ferroelectrics have been explored for energy storage property. Particularly slim polarization hysteresis (P-E) loops are observed in 0.655Bi0.5Na0.5TiO3-0.065BaTiO3-0.28Bi0.2Sr0.7□0.1TiO3 (6.5BNBT-BST) at ambient temperature resulting in a giant recoverable energy density (Wrec = 1.5 J cm−3) and extremely high efficiency (η = 90%) at 100 kV cm−1, which are closed related to the track of P-E loops. As the addition of Bi0.2Sr0.7TiO3 (BST) content, the ergodic relaxor phase becomes dominant with dynamic polar nano-regions attributed to the absence of ferroelectric domain in the relaxor phase. Furthermore, the recoverable energy density exhibits small variation in elevated temperature where the depressed polarization is compensated by almost hysteresis free loops (η up to 97%). The achievement of these characteristics in P-E loops provides that Bi0.2Sr0.7TiO3 tailoring by A-site vacancies is a potential route when designing new relaxor ferroelectrics for energy-storage applications.

Influence of lead titanate additive on the structural and electrical properties of Na0.5Bi0.5TiO3-SrTiO3 piezoelectric ceramics

Investigations of the structural and electrical properties of 0.40Na0.5Bi0.5TiO3-(0.6-x) SrTiO3- xPbTiO3 quaternary solid solutions (x = 0.08, 0.18, and 0.28) are presented in this paper. The solid solutions are synthesized using solid-state reaction techniques. X-ray diffraction (XRD) studies reveal that the solid solution is homogeneous and has a tetragonal structure with space group (P4mm) as well as the co-existence of tetragonal and cubic phases with 0.08 mol% lead titanate. The surface morphology of the material is observed using SEM, and reductions in grain sizes are observed with increasing PT. The dielectric properties of this solid solution, measured between room temperature and 673 K in the frequency range 1–100 kHz, showed good relaxor behaviour. The maximum dielectric constant (εr) ~ 3144 is observed at 413 K. Excellent P-E hysteresis loops for this solid solution confirm good ferroelectric properties, exhibiting a maximum at 55 kV/cm. Remanant polarization (Pr) and coercive field (EC) exhibit an increasing, decreasing and then a subsequent increasing trend with the increase in PT concentration. The piezoelectric coefficient (d33) measured on the poled samples exhibited a maximum of ~ 89 pC/N. The estimated energy storage density, (W) ~ 0.30 J/cm3, showed a superior energy storage performance. The excellent dielectric, piezoelectric and ferroelectric properties of the sodium bismuth titanate - strontium titanate-lead titanate system implied that the structure of the solid solutions approached the morphotropic phase boundary region, which enhances its potential for use in sensor and actuator applications.

Insight into the structure and functional application of Mg-doped Na0.5Bi0.5TiO3 electrolyte for solid oxide fuel cells

Na0.5Bi0.5TiO3 (NBT) and its acceptor-doped perovskites, as lead-free piezoelectric materials before, have been found to be excellent oxygen-ion conductors with potential applications in intermediate-temperature solid oxide fuel cells (SOFCs). Among them, the Bi deficient and B-site Mg doped sodium bismuth titanate (Na0.5Bi0.49Ti0.98Mg0.02O2.965, NBTM) exhibits a remarkable oxygen ionic conductivity. Here, we report a structural analysis on NBT and NBTM ceramics using high-temperature in situ neutron diffraction (NPD) to gain insight into the effects of Mg doping on ionic conductivity and structure. Both perovskite oxides exhibit two consecutive phase transformations from R3c to P4bm at ∼400 °C and from P4bm to Pm3¯m at ∼600 °C. The effects of Bi deficiency and Mg substitution on oxygen vacancy concentration and ion displacements are revealed. In addition, a NBTM supported single cell consisting of Ag-NBTM cathode and Ni-NBTM anode is fabricated to evaluate the possibility of its application in intermediate-temperature SOFCs. The structural stability of NBTM is still a major concern that hinders its utilization at high temperature and under reducing atmosphere.

Structural, dielectric and impedance characteristics of (Bi0.5Na0.5)TiO3-BaTiO3 electronic system

A lead-free solid solution of two ferroelectrics, bismuth sodium titanate and barium titanate, of a composition 0.96(Bi0.5Na0.5TiO3)-0.04(BaTiO3) (termed as BNT-BT-4) was prepared by a standard low-cost ceramic technology. The phase analysis of the solid solution, carried out using X-ray diffraction pattern, shows a major tetragonal phase and a minor impurity phase at room temperature. The surface morphology of the prepared system showed the formation of the high-density sample. The phonon mode statistics, width location and intensity of the peaks were analyzed by Raman spectroscopy. The temperature-frequency dependence of dielectric parameters (permittivity and tangent loss) and AC conductivity were analyzed. The apparent activation energy of BNT-BT-4 was evaluated with help of AC conductivity data. The effect of grain on the capacitive and resistive properties has been studied using an impedance spectroscopy technique. The decrease in the value of grain resistance on rising temperature shows the semiconductor or negative temperature coefficient behavior of the material. Based on an analysis of complex modulus spectrum, the conduction mechanism in the material has been suggested. As BNT-BT-4 shows a remarkable temperature independent relative dielectric properties and low tangent loss, it is a potential candidate for devices.

Structural, optical, and Raman studies of Gd doped sodium bismuth titanate

The effects of gadolinium (Gd) on lead free sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) ceramics are investigated. X-ray diffraction (XRD) studies indicate that perovskite phase (rhombohedral, R3c) is formed for all Gd doped NBT (Gdx:NBT) compositions (x = 0, 0.02, 0.04, 0.06, 0.08). XRD peak shifts to the higher angles for all compositions except for x = 0.08. Amphoteric nature of Gd in NBT sites are observed i.e., it occupies Bi-site up to x = 0.06 and then distributes to Ti-site. Octahedral distortion (c/a) increases in the range 0.02 ≤ x ≤ 0.06 and then decreases. Raman spectra suggest that the introduction of Gd+3 ion induces structural changes without disturbing the long range order. The material can be readily excited using UV (360 nm) and shows emission peaks at ~592 nm and 687 nm. Optical property evaluation indicates that the lowest band gap (Eg = 2.78 eV) is observed at x = 0.08. When x > 0.04, the photoluminescence (PL) intensity decreases indicating the onset of concentration quenching. The critical energy distance (found to be 14 Å) and Dexter's theory based analysis indicate that concentration quenching is attributable to multipole-multipole (specifically dipole-dipole) interactions in the system. Commission International de Eclairage (CIE) chromatic color coordinates are reported for all doped systems; the observed patterns mirror PL analysis results. For instance, PL intensity shrinks beyond 4 at%; this corresponds to a regression in the CIE trajectory with respect to concentration.

Specific Features of the Structure and Properties of High-Temperature Oxide Materials Based on Bismuth Sodium Titanate

Single-phase ceramic samples from the region of morphotropic phase boundary in the (1–x)(Na0.5Bi0.5)TiO3–xBaTiO3 and (1–y)[(Na0.5Bi0.5)TiO3–xBaTiO3]–yBi(Mg0.5Ti0.5)O3 systems, modified by low-melting LiF and 0.6NaCl–0.4LiF additives, have been prepared by solid-state synthesis. The effect of additives on the phase formation, structural parameters, and dielectric and ferroelectric properties of the ceramics has been studied. A decrease in the ceramic sintering temperature is found. A slight increase in the unit-cell volume upon modification of the ceramics under study by lithium fluoride and 0.6NaCl–0.4LiF additive is revealed. First-order ferroelectric phase transitions near 700–800 K have been observed. The prospects for improving the piezoelectric properties of modified ceramic samples are proved.

Ferroelectric Phase Transitions in Non-Stoichiometric Sodium-Bismuth Titanate Ceramics

Features are studied of the phase formation, structural parameters, microstructure, and dielectric and ferroelectric properties of non-stoichiometric (Na0.5 + xBi0.5)TiO3 ceramics with x = 0–0.1. The investigated samples exhibit ferroelectric phase-transition behavior as anomalies and peaks in dielectric permittivity near 400 and 600 K, respectively. Study of the second harmonic generation shows that phase transitions near 400 K exhibit relaxor-type behavior, indicating there are polar regions in the nonpolar matrix. An increase in the Na/Bi ratio in the initial compositions improves the dielectric and ferroelectric properties of the ceramics.

Electrical conductivity study of B-site Ga doped non-stoichiometric sodium bismuth titanate ceramics

The present investigation looks at the effect of Ga3+ doping for B-site Ti4+ on the phase stability and oxygen-ion conductivity of Na0.54Bi0.46TiO3-δ for the possible electrolyte application in low-temperature solid oxide fuel cells. Dense bulk samples were prepared using the conventional solid-state route. Although XRD revealed the presence of a single rhombohedral perovskite phase, SEM study indicated the existence of impurity phase in the form of fibers in the as-sintered samples. The local chemical compositional analysis showed Na/Bi molar ratio to be > 1 in the perovskite phase of all the tested compositions and the existence of Na2Ti6O13 compound in the impurity phase. Impedance spectroscopy studies suggested a monotonous decrease in bulk conductivity on Ga3+ doping on the B-site of Na0.54Bi0.46TiO3-δ. The bulk conductivity of 7.8 mS/cm measured in Na0.54Bi0.46TiO3-δ at 600 °C declined to 5.8 mS/cm on 2 at.% Ga3+ doping. The conductivity reduction was attributed to the formation of local defect clusters which act as sinks, and thus leads to decrease in the concentration of free oxygen vacancy. Although not much change in initial bulk conductivity of Na0.54Bi0.46Ti0.99Ga0.01O3-δ was found under various atmospheres from 500 °C to 600 °C, the annealing study carried out at 600 °C for 12 h under 5% H2–95% N2 condition showed the decomposition of perovskite phase to form metallic Bi. Both pure and Ga-doped samples showed a considerable conductivity degradation of 12% after 100 h ageing in air at 600 °C. The phenomenon related to the formation of local defect clusters over time was proposed to be a possible reason for the observed conductivity decay.

Ultrahigh strain in site engineering-independent Bi0.5Na0.5TiO3-based relaxor-ferroelectrics

In the past, accompanied by the highly asymmetric bipolar strain-electric field (S-E) loop, the ultrahigh strain can be realized in bismuth sodium titanate (BNT)-based ceramics mainly by the B site doping, which seriously restricts the further opening of the research and application scope. Here, regardless of A or/and B sites doping, we observed an ultrahigh unipolar strain response (S = 0.53–0.56% and d33* = 883–933 pm/V, 60 kV/cm) in [Bi0.5(Na0.82-xK0.18Lix)0.5](1-y)Sry(Ti1-zTaz)O3 ceramics by chemical modifications, accompanied by the even higher unipolar strain (∼0.63%, 90 kV/cm) and large field signal (d33* = 990 pm/V, 50 kV/cm). Moreover, the symmetrical bipolar S-E loop is also obtained in this system. In particular, we strictly illuminate the origin of the composition-induced giant strain from the view of the microscopic (A-O bonds weakening), mesoscopic (the coexistence of metastable small-sized ferroelectric domain structures and ergodic relaxor phase), and macroscopic (Tf-r shifting) perspectives. We believe that this work can provide a simple but effective way to optimize the strain behavior in BNT-based ceramics.

Improvement of ionic conductivity in A-site lithium doped sodium bismuth titanate

Oxide-ion conductors play a significant role in various applications such as solid oxide fuel cells (SOFCs), oxygen separation membranes and sensors. Recently, high ionic conductivity (~1×10−4Scm−1 at 600°C) was found in sodium bismuth titanate (NBT), which originates from oxygen vacancies compensating the introduced Bi-deficiency. By providing pathways with low diffusion barriers, the highly polarizable Bi3+ ions with 6s2 lone pair electrons and weak BiO bonds are also beneficial for the migration of oxygen ions. Here we report the influence of lithium doping on the electrical properties of NBT. The optimal doping level of 4at% Li on the Bi-site improves the ionic conductivity by one order of magnitude to ~7×10−3Scm−1 at 600°C without changing the conduction mechanism, which could be attributed to an increase in the oxygen vacancy concentration based on an acceptor doping mechanism. A further increase in Li content does not improve the total conductivity. Oxygen diffusion data were acquired by the Isotope Exchange Depth Profile (IEDP) method in combination with Secondary Ion-Mass Spectrometry (SIMS). The oxygen self-diffusion coefficients (e.g. 7.04×10−9cm2s−1 at 600°C) are in excellent agreement with the values derived from impedance spectroscopy data, suggesting that the oxygen ions are the main charge carriers in the system. Furthermore, a degradation test was performed for 100h under a variety of atmospheres, showing only a slight decrease in conductivity in both air and oxygen atmospheres attributed to the loss of material from the A-site. Comparison with other oxide-ion conductors indicates that Li-doped NBT materials are promising candidates for intermediate temperature SOFC applications.

High temperature ultrasonic sensor for fission gas characterization in MTR harsh environment

In the contemporary world, the measurements in hostile environment is one of the predominant necessity for automotive, aerospace, metallurgy and nuclear plant. The measurement of different parameters in experimental reactors is an important point in nuclear power strategy. In the near past, IES (Institut d’Électronique et des Systèmes) on collaboration with CEA (Commissariat à l’Energie Atomique et aux Energies Alternatives) have developed the first ultrasonic sensor for the application of gas quantity determination that has been tested in a Materials Testing Reactor (MTR). Modern requirements state to labor with the materials that possess stability on its parameters around 350°C in operation temperature. Previous work on PZT components elaboration by screen printing method established the new basis in thick film fabrication and characterization in our laboratory. Our trials on Bismuth Titanate ceramics showed the difficulties related to high electrical conductivity of fabricated samples that postponed further research on this material. Among piezoceramics, the requirements on finding an alternative solution on ceramics that might be easily polarized and fabricated by screen printing approach were resolved by the fabrication of thick film from Sodium Bismuth Titanate (NBT) piezoelectric powder. This material exhibits high Curie temperature, relatively good piezoelectric and coupling coefficients, and it stands to be a good solution for the anticipated application. In this paper, we present NBT thick film fabrication by screen printing, characterization of piezoelectric, dielectric properties and material parameters studies in dependence of temperature. Relatively high resistivity in the range of 1.1013 Ohm.cm for fabricated thick film is explained by Aurivillius structure in which a-and b-layers form perovskite structure between oxides of c-layer. Main results of this study are presented and discussed in terms of feasibility for an application to a new sensor device operating at high temperature level (400°). Piezoelectric parameters enhancement and loss reduction at elevated temperatures are envisaged to be optimized. Further sensor development and test in MTR are expected to be realized in the near future.

Atomistic simulations of ion migration in sodium bismuth titanate (NBT) materials: towards superior oxide-ion conductors

Fabricating (111)-ordered NBT and avoid any A-site vacancies will yield even higher oxide-ion conductivities.

Ionic Conduction and Anomalous Diffusion in Sr and Ga Acceptors Co-Doped Bismuth Sodium Titanate Solid Solutions

Recently, ferroelectrics of Bi0.5Na0.5TiO3 (BNT) based perovskite-structured oxides that exhibit ionic conductive grain have attracted great attention, and been proved to be highly dependent on the chemical composition. Herein, effects of Sr and Ga acceptors co-doping on the impedance characteristics and electric properties of non-stoichiometric BNT ceramics were studied. It indicates that the conductivity of BNT ceramics is significantly improved after introducing a certain amount of Sr and Ga, where the grain conductivity and grain boundary conductivity can be clearly distinguished. The inhomogeneity is reflected in which the acceptors preferentially diffuse along the grain boundaries with the change in activation energy. The conductivity could be influenced associated with dopant-vacancy defect complexes as the increasing of dopant content and sintering time. Ionic dominated conductive properties easily mixed with electronic contribution can be derived at different atmospheres. The degree of diffuseness and relaxation are enhanced monotonically with dopant concentration that revealed by a modified Curie-Weiss law at the high frequency.

Multifunctional Nd3+ substituted Na0.5Bi0.5TiO3 as lead-free ceramics with enhanced luminescence, ferroelectric and energy harvesting properties.

Herein, we present comprehensive investigations of the optical and electrical properties of Nd3+ substitution in sodium bismuth titanate ceramics (NBNT) with varying Nd3+ concentration. The room temperature photoluminescence (PL) emission for both unpoled and poled samples is observed to be a maximum for an Nd3+ substitution of 1 mol%. Upon poling, the PL intensity is observed to be quenched, consistent with the obtained XRD data, indicating an electric-field induced structural ordering towards higher symmetry, confirmed with the help of structural refinement. The evaluated ferroelectric to relaxor and antiferroelectric relaxor T(F–R) was observed clearly from the poled dielectric–loss curve for the 1 mol% of Nd3+ substitution. Furthermore, the optimized NBNT exhibited a lower Ec and a higher off-resonance figure of merit (FOMoff) for energy harvesting by 12% and 30%, respectively, in comparison with un-doped NBT.

Structural properties and Doping effects of ferroelectric ceramics (Na0.2Bi0.3Zr0.5) TiO2

Lead free Sodium Bismuth Titanate Zirconate (Na0.2Bi0.3Zr0.5) TiO2 or NBZT Solid solution were prepared by Mixed Oxide Conventional route. Moreover, their Phase Structure and luminescence properties were investigated for storage device applications. Primarily XRD analysis indicated that mixed phase structure at the higher annealing temperature. X ray powder Diffraction Data were used for a quantitative Structural investigation. SEM results for spherical and cuboid particles were observed. Based on results we can say that average grain diameter for NBZT is around 100-200 nm. Ferroelectrics perovskites has optical properties, which is shown in photo luminescence emission and absorption Spectra. Photoluminescence arises when excited by photon so in this present work excitation band at 390 nm (3.2 eV).we say that hard and soft Ferro electric ceramics. Peaks are observed between 2.76 eV to 4.10 eV from the emission spectra. Absorption spectra are used for excitation wavelength.

Resistive, capacitive and conducting properties of Bi0.5Na0.5TiO3-BaTiO3 solid solution

In the present paper, the effect of addition of a small amount (8wt%) of barium titanate (BT) on electrical properties of bismuth sodium titanate (BNT) forming a solid solution of a composition (0.92)(Bi0.5Na0.5TiO3)+(0.08)(BaTiO3) (BNT-BT-8) has mainly been reported. The solid solution of BNT-BT-8 was prepared by a cost effective and standard mixed-oxide method. Preliminary structural analysis using X-rays diffraction pattern and data showed the existence of two phases; orthorhombic (major) and tetragonal (minor impurity/secondary) phase. Analysis of scanning electron micrograph and energy dispersive spectrum of the pellet sample reveals the formation of high density with homogeneously distributed grains of varying dimension. The locations, phonon modes statistics, width and intensity of peaks of Raman spectra of BNT-BT-8 was analyzed by Raman spectroscopy and provided some data on molecular structure of the material. The effect of temperature and frequency on some ferroelectric characteristics of the material were studied. The frequency-temperature dependence of electrical characteristical such as impedance of the material was studied by impedance spectroscopy. The electric conductivity follows the Arrhenius equation and provided activation energy at different frequency. The dielectric and impedance spectroscopy suggest the existence of a non-Debye relaxation mechanism in the material.

Structural and electrical characteristics of barium modified bismuth-sodium titanate (Bi0.49Na0.49Ba0.02)TiO3

The lead-free polycrystalline ceramic, barium titanate modified bismuth–sodium titanate 0.98 (Bi0.5Na0.5TiO3) + 0.02 BaTiO3 (BNT–BT-2) was synthesized by using a mixed oxide route at high temperature. The structural (crystal structure, microstructure, molecular structure), and electrical (dielectric constant and loss, impedance, conductivity) characteristics of the parent compound (Bi0.5Na0.5TiO3) have greatly been influenced by the addition of even a small amount of barium titanate in it. Preliminary structural study of BNT–BT-2 using X-ray diffraction data clearly shows the formation of a single-phase perovskite structure with the coexistence of hexagonal (major phase) and tetragonal (minor) phases. The existence of diffuse phase transtition and the relaxor behaviour in the material is confirmed by analysis of temperature-frequency dependence of dielectric parameters. The composition (0.98BNT − 0.02BT) of the material shows non-Ohmic conduction in its J–E characteristics. In this lead-free ceramic, permittivity anomalies are matched to modulus anomalies. The highlighted features are determined by structural phase transitions of the ferroelectric-like.

Room-Temperature Large and Reversible Modulation of Photoluminescence by in Situ Electric Field in Ergodic Relaxor Ferroelectrics

Ferroelectric oxides with luminescent ions hold great promise in future optoelectronic devices because of their unique photoluminescence and inherent ferroelectric properties. Intriguingly, the photoluminescence performance of ferroelectric ceramics could be modulated by an external electric field. However, researchers face a current challenge of the diminutive extent and degree of reversibility of the field-driven modification that hinder their use in room-temperature practical applications. Within the scope of current contribution in rare-earth-doped bismuth sodium titanate relaxors, the most important information to be noted is the shifting of the depolarization temperature toward room temperature and the resulting considerable enhancement in ergodicity, as evidenced by the dielectric properties, polarization, and strain hysteresis, as well as the in situ Raman/X-ray diffraction studies. After the introduction of 1 mol % Eu, the induced composition and charge disorders disrupt the original long-range ferroelectric macrodomains into randomly dynamic and weakly correlated polar nanoregions, which facilitates a reversible transformation between polar nanoregions and unstable ferroelectric state under an electric field, engendering a large strain. By virtue of this, both the extent and degree of reversibility of photoluminescence modulation are enhanced (∼60%) considerably, and room-temperature in situ tunable photoluminescence response is then achieved under electric field. These should be helpful for the realization of regulating the physical couplings (photoluminescent-ferroelectrics) in multifunctional inorganic ferroelectrics with a high ergodic state by reversibly tuning the structural symmetry.

Synthesis, Structure and Luminescence of Dy Doped Na0.25K0.25Bi0.5TiO3

Bismuth sodium titanate (NBT) is one of the most promising lead-free piezoelectric material suitable to replace widely used lead-based piezoelectric materials. With general formula A+ 0.5Bi3+ 0.5Ti4+O3, where A = Na+ or K+, perovskite structure can crystallise in rhombohedral, cubic or tetragonal phase, depending on temperature and type (content) of monovalent cation. Doping this material with optically active ions, such as Dy3+, provides a new phosphor material with potentially interesting combination of piezoelectric and luminescence properties. In this work we demonstrate the preparation of Na0.25K0.25Bi0.48Dy0.02TiO3 powder material. The material was synthesized via solid-state reaction by using TiO2, Bi2O3, Na2CO3, K2CO3 and Dy2O3 as precursor materials. These powders were ball milled in ethanol for 12 h, then dried and calcined at 850°C for 2 h. Subsequently, obtained powder was additionally milled in ethanol for additional 12 h, and finally sintered at 850°C for 4 h. Structural analysis was done by X-ray diffraction and showed tetragonal P4bm structure without impurities. Optical characterization including photoluminescence excitation and emission spectra and diffuse reflection measurements were performed. Emission spectra showed characteristic bands of Dy3+ ions with pronounced emissions originating from f–f electronic transitions. A dominant band in the blue region with maximum at around 477 nm originates from magnetic-dipole 4F9/2→6H15/2 transition, and another in the yellow region with maximum at around 574 nm originates from electric-dipole 4F9/2→6H13/2 transition. A small intensity higher energy band cantered at around 457 nm originates from 4I15/2→ 6H15/2 transition provides the possibility to use this type of emitting material as temperature sensor using the LIR method.