Eu Single Crystals Research Articles

Spectroscopic studies of Eu doped CaF2 single crystal

The Eu-doped CaF2 crystal is investigated for potential use in visible-region solid-state lasers. The single-crystal Eu: CaF2 has an FCC crystal structure and belongs to the space group Fm-3 m, as confirmed by single-crystal X-ray diffraction. A Raman shift of 324 cm−1 has been observed in a single crystal of Eu: CaF2. The vibrational mode at low frequency is suitable for minimizing non-radiative emissions and increasing radiative emissions. Eu: CaF2 crystal has two absorption bands, at 399 nm and 415 nm, corresponding to the 7F0→5L6 and 7F0→5D3 transitions, respectively. The strongest absorption peak (399 nm) is associated with the 7F0→5L6 electronic transition. The orange-red emission was observed at 588 nm (5D0→7F1), 612 nm (5D0→7F2), 648 (5D0→7F3), and 685(5D0→7F4) when excited at 399 nm. Measurements of the luminescence intensity ratio (R) between the 5D0→7F2 (electric dipole) transition and the 5D0→7F1 (magnetic dipole) transition predict that Eu3+ ions are situated at the symmetric sites in CaF2. The radiative parameters for the Eu: CaF2 crystal are calculated using the JOES code using the Judd-Ofelt theory. The calculated total radiative transition probability (AR) is 64.54 s−1, and the radiative lifetime (τR) is 15.57 ms. Radiative transition probabilities are 43.41,7.02 and 14.10, and branching ratios are 67.26 %,10.88 % and 21.85 % for 5D0→7F1, 5D0→7F25D0→7F4 transitions respectively.

Optically-stimulated luminescence and thermoluminescence properties of RbI:Eu single crystals

Optically-stimulated luminescence (OSL) and thermoluminescence (TL) properties of RbI:Eu single crystals synthesized by the vertical Bridgman-Stockberger method were evaluated. OSL peak at 430 nm due to 4f65d1-4f7 transition of Eu2+ was observed under stimulation at 750 nm. The 0.5% Eu-doped sample exhibited the highest OSL intensity among all the sample, and the detection limit was 1 mGy. TL glow peaks at ∼100 and ∼200 °C were observed and were ascribed to Fz-center (F-center near Eu2+-cation vacancy dipole) and F-center, respectively. The 0.5% Eu-doped sample showed the highest TL intensity among all the sample, and the detection limit was 0.01 mGy.

Composition and Surface Optical Properties of GaSe:Eu Crystals before and after Heat Treatment.

This work studies the technological preparation conditions, morphology, structural characteristics and elemental composition, and optical and photoluminescent properties of GaSe single crystals and Eu-doped β-Ga2O3 nanoformations on ε-GaSe:Eu single crystal substrate, obtained by heat treatment at 750-900 °C, with a duration from 30 min to 12 h, in water vapor-enriched atmosphere, of GaSe plates doped with 0.02-3.00 at. % Eu. The defects on the (0001) surface of GaSe:Eu plates serve as nucleation centers of β-Ga2O3:Eu crystallites. For 0.02 at. % Eu doping, the fundamental absorption edge of GaSe:Eu crystals at room temperature is formed by n = 1 direct excitons, while at 3.00 at. % doping, Eu completely shields the electron-hole bonds. The band gap of nanostructured β-Ga2O3:Eu layer, determined from diffuse reflectance spectra, depends on the dopant concentration and ranges from 4.64 eV to 4.87 eV, for 3.00 and 0.05 at. % doping, respectively. At 0.02 at. % doping level, the PL spectrum of ε-GaSe:Eu single crystals consists of the n = 1 exciton band, together with the impurity band with a maximum intensity at 800 nm. Fabry-Perrot cavities with a width of 9.3 μm are formed in these single crystals, which determine the interference structure of the impurity PL band. At 1.00-3.00 at. % Eu concentrations, the PL spectra of GaSe:Eu single crystals and β-Ga2O3:Eu nanowire/nanolamellae layers are determined by electronic transitions of Eu2+ and Eu3+ ions.

Single crystal growth of 2 in. diameter LiI:Eu in carbon coated crucible and effect of post growth thermal treatment on scintillation

This study focuses on economically and efficiently growing 2-inch diameter, 2-inch length LiI:Eu single crystals using Bridgman technique in carbon coated quartz crucible. Further, the impact of growth rate variation to expedite crystal growth is investigated and the influence of heat treatment on grown crystal and its scintillation properties is explored. Our research demonstrates more than 1.5-fold improvement in the scintillation light yield after heat treatment for the LiI:Eu crystals grown at translation rate of 2.5 mm/hr. Furthermore, more than twofold enhancement in scintillation light yield for both gamma and thermal neutron radiations in LiI:Eu crystals grown at 1 mm/hr rate is observed after vacuum heat treatment at 300 °C.

Effects of chemical composition control of colquiriite-type neutron scintillator single crystals

In this study, charge compensation was performed by co-doping Na + ions at the Ca2+ sites of Ce-doped LiCaAlF6 single crystals to prevent the generation of cation vacancies owing to Ce3+-doping at the Ca2+ sites. Consequently, an improved radiation resistance and increased light yield under neutron irradiation was achieved. In contrast, the Al metal of the starting material used as a substitute for AlF3 significantly increased the effective segregation coefficient keff of the Eu2+ ions in Eu-doped LiCaAlF6 and Eu-doped LiSrAlF6 single crystals. The Al metal and EuF3 in the starting materials produced EuF2 via a chemical reaction, and the Eu2+ ions in EuF2 could be substituted at the Ca2+ and Sr2+ sites. In addition, the Ca/Sr ratio control of the Li(Ca,Sr)AlF6:Eu solid-solution scintillator single crystals improved the light yield through band-gap control, and the Li(Ca,Sr)AlF6:Eu single crystal with a 25% Sr concentration exhibited the highest light yield.

Spectral properties and β-ray scintillation of GdVO4:Eu single crystals grown by the floating zone method

GdVO4:Eu single crystals were successfully grown along the [110] direction by the floating zone method. The grown crystals had no cracks and inclusions for any Eu-concentration. The polarizing microscopy proved that the grown crystal contained no microscopic defects such as low-angle grain boundaries and inclusions. The crystal showed red fluorescence with the peak wavelength of 620 nm. The emission showed strong polarization dependence; the emission of π-polarization is more intensive than that of strongly the σ-polarization. Under irradiation of X-ray or electron beam, the crystals also showed strong red fluorescence based on the host excitation. The fluorescence lifetime was measured to be about 785 μs. Scintillation the GdVO4:Eu single crystals for β-ray was successfully demonstrated using nuclear medicine 18F-fludeoxyglucose.

Effects of two strategies on afterglow behavior of Lu2O3:Eu single crystal scintillator: Co-doping with Pr3+ and solid solution with Sc2O3

In this paper, effect of two strategies on afterglow behavior of Lu2O3:Eu single crystal scintillator, Pr3+ co-doping and solid solution with Sc2O3, were studied systematically. Two groups of Lu2O3:5 at%Eu,x at%Pr (x = 0, 0.2, 0.5, 1, 2 and 5) and (Lu1–yScy)2O3:5 at%Eu (y = 0, 20 at%, 50 at% and 70 at%) single crystals were grown by floating zone (FZ) method in air atmosphere. The structures of as-grown crystals were determined by X-ray diffraction (XRD). The scintillation, photoluminescence properties and carrier trap states were investigated through afterglow, X-ray excitation luminescence (XEL), transmittance, photoluminescence excitation (PLE) and photoluminescence (PL), PL decay and thermal stimulated luminescence (TSL) curves. It is found that with the increase of Pr3+ concentration, the afterglow level of the system decreases at the expense of scintillation luminescence efficiency. Meanwhile, although Sc2O3:Eu presents much lower afterglow intensity than Lu2O3:Eu, the addition of Sc2O3 will just increase the afterglow level of the (Lu1–yScy)2O3:5 at%Eu single crystal system. Possible mechanisms for above phenomena are discussed based on experimental results.

Cerium Bromide Single-Crystal X-Ray Detection and Spectral Compatibility Assessment with Various Optical Sensors

Scintillators with high light yield (LY) values are of interest for medical imaging applications, in harsh environments, nondestructive testing (NDT), etc. CeBr3 has a LY of 60000 photons per MeV, a value much higher than other efficient materials, such as Lu3Al5O12:Ce (25000 photons/MeV); thus, its X-ray detection properties would be of interest to be examined for medical imaging applications. The X-ray detection and absorption properties of a single crystal CeBr3 sample along with the compatibility of its produced light with various optoelectronic sensors were examined. In this study, the quantum detection (QDE) and the energy absorption efficiency (EAE) of CeBr3 were calculated. The findings were compared with data for 10 × 10 × 10 m m 3 Lu3Al5O12:Ce and CaF2:Eu single crystals. The measured optical spectrum produced by CeBr3 was well correlated with the spectral response of commercial optical sensors, yielding spectral matching higher than 93% for various photocathodes, e.g., GaAs (94%), E-S20 (95%), and bialkali and multialkali (95-97%), as well as with flat panel position-sensitive photomultipliers (95-99%). The energy absorption properties of CeBr3 were found higher than those of Lu3Al5O12:Ce and CaF2:Eu for X-ray tube voltages greater than 100 kVp. The quantum detection efficiency was 100% across the examined energy range. Even though CeBr3 is hygroscopic and has a mediocre 5.1 g/cm3 density, the QDE, EAE, and spectral correlation results are promising for medical imaging applications.

Effects of different Eu concentrations and Cu, Mg or Ba ions co-doping on optical and scintillation properties of LiCaAlF6:Eu single crystals

LiCaAlF6 single crystals doped with different Eu concentrations varied from 1 at% to 5 at%, and LiCaAlF6:Eu single crystals co-doped with 3 at%Cu+, 2 at%Mg2+, 2 at%Ba2+ were grown by the Bridgman method in non-vacuum atmosphere. Their optical and scintillation performances were studied. The optimal scintillation efficiency was achieved in the LiCaAlF6:Eu single crystals with Eu concentrations between 2 and 2.5 at%. The influences of Cu+, Mg2+ and Ba2+ co-doping on optical properties, scintillation yield, scintillation decay and defect structures were studied. It was found that the Cu+ co-doping can improve the scintillation efficiency. The Mg2+ and Ba2+ co-doping have negligible effects on light yield.

Comparison of Photoluminescence and Scintillation Properties Between Lu₂O₃:Eu Single Crystal and Transparent Ceramic

Lu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :Eu single crystals (SCs) and transparent ceramics (TCs) were prepared by the optical floating zone (OFZ) method and hot isostatic pressing (HIP) sintering method, respectively. Their photoluminescence (PL) and scintillation properties, including photoluminescence excitation (PLE) and PL, PL decay, X-ray excited luminescence (XEL) and afterglow level curves, were measured and compared. Their transmission spectra were also recorded. The differences of the PL and scintillation performance between the Lu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :Eu SC and TC have been studied. It is shown that the transmittance of the SC is higher than that of the TC, reaching as high as 80%. The Eu( S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> )→ Eu(C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) energy transfer states in the SC and TC are comparable through investigating the PL and PL decay curves. The main difference between the SC and TC in this work comes from the scintillation luminescence efficiency and afterglow level. The XEL intensity of the SC is 2.4 times that of the TC. The afterglow level of the TC is significantly higher than that of the SC, which probably results from the carrier traps formed in the forbidden gap related to the grain interface in ceramics sample.

Properties of axion insulator candidate layered Eu&lt;sub&gt;1–&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ca&lt;i&gt;&lt;sub&gt;x&lt;/sub&gt;&lt;/i&gt;In&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt;

The study of two-dimensional (2D) magnetic materials has driven the development of modern nano-electronic devices. Exploration of novel intrinsic layered materials with 2D magnetic order will provide a material candidate pool for fabricating 2D devices and searching for new quantum phases. Recently the layered antiferromagnetic (AF) topological insulators have aroused the great interest of researchers. As one of the proposed axion insulators, EuIn&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt; exhibits a layered structure and 2D AF order. It is found that the parent compound EuIn&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt; exhibits metallic behavior instead of the predicted insulating feature. To pursuit the predicted non-trivial topological state and novel feature, in this paper, we use various elements to dope the system to adjust the Fermi level. It is found that only Ca is successfully doped into the EuIn&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt; system. The systematic transport and magnetization studies are performed on the single crystal of Eu&lt;sub&gt;1–&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ca&lt;i&gt;&lt;sub&gt;x&lt;/sub&gt;&lt;/i&gt;In&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt;. The long-range AF order is revealed to be similar to the parent compound. Above the AF transition, the magnetization violated Curie-Weiss behavior and magnetoresistance keeps negative, indicating the ferromagnetic order. With doping nearly 20% non-magnetic Ca, the magnetic properties of the system barely change, which is favorable to keeping the former predicted nontrivial topological properties in EuIn&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt;. Although Ca shares the same valence with Eu, the carrier density of Eu&lt;sub&gt;1–&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ca&lt;i&gt;&lt;sub&gt;x&lt;/sub&gt;&lt;/i&gt;In&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt; is one order lower than that of EuIn&lt;sub&gt;2&lt;/sub&gt;As&lt;sub&gt;2&lt;/sub&gt;. The Ca doping brings electrons in and lifts the Fermi level. The results enrich the 2D magnetic material candidate pool and provide useful information for realizing the nontrivial topological state in the 2D AF system.

Optical and Scintillation Properties of Hf⁴⁺ Codoped SrI₂:Eu²⁺ Single Crystals

Single crystals of Eu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> -activated SrI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , one of the most leading-edge scintillators for gamma-ray spectroscopy applications, have a low radioactive background, excellent energy resolution of 2.6%–3% at 662 keV, and high light yield of 80 000–120 000 photons/MeV. In this article, tetravalent ions codoping, namely, Hf <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4+</sup> codoping, was used to enhance its scintillation performance. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\emptyset 12$ </tex-math></inline-formula> mm diameter SrI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> :Eu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> single crystals codoped with 0, 0.05, 0.1, and 0.2 at% Hf <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4+</sup> were successfully grown by the multiampoule Bridgman method. All grown crystals are highly transparent, crack-free, and inclusion-free. The effects of Hf <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4+</sup> codoping concentration on the optical and scintillation properties were studied. The gamma-ray energy resolutions of SrI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> :Eu single crystals can be improved from 3.4% to 3.1% at 662 keV, and from 6.6% to 6.0% at 122 keV upon 0.05 at% Hf <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4+</sup> codoping.

VUV spectroscopy of lanthanide doped fluoride crystals K2YF5

K2Y0.99Ln0.01F5 (Ln = Ce, Eu and Sm) single crystals have been synthesized by the hydrothermal technology. The optical properties of Ce3+ and Eu3+ ions doped into K2YF5 matrix have been studied under excitation in the deep UV and vacuum UV (VUV) region. The obtained data from excitation spectra and Dorenbos models have been used to predict the energies of the f-d and charge transfer transitions as well as the energy levels location of divalent (Ln2+) and trivalent (Ln3+) lanthanide ions within the band gap of K2YF5. In particular, the f-d and charge-transfer transitions of Sm3+ in the luminescence excitation spectrum of K2YF5:Sm3+ have been identified. The host referred binding energy (HRBE) and vacuum referred binding energy (VRBE) schemes have been constructed for Ln2+ and Ln3+ ions doped K2YF5 crystal which were used for the analysis of possible applications of K2YF5 doped with Ln3+ ions as thermoluminescence materials.

Luminescence efficiency of CaF2:Eu single crystals: Temperature dependence

During the last decades, there is increasing interest in applications of scintillators at harsh environments (i.e., high temperatures or radiation fluxes), such as in geophysical detectors for deep geology boreholes, non-destructive testing (NDT) of pipelines in oil and gas industry, space and marine exploration, nuclear reactor monitoring, radiation chemistry, etc. To this aim, the current study is the first step towards the investigation of the luminescence efficiency dependence of single-crystal scintillators over wide temperature ranges. Calcium fluoride doped with europium (CaF2:Eu) was selected due to the fact that it has a high melting point at 1418°C and is also robust to mechanical and thermal shocks. The dimensions of the single-crystal sample were 10x10x10 mm3, and it was irradiated using typical X-ray radiographic exposures (90 kVp, 63mAs) in order to measure the light photon intensity dependence with temperature (22 to 128 °C). The luminescence efficiency was found maximum at the lowest examined temperature (22.01 efficiency units-E.U. at 22 °C-environmental). With increasing temperature, the luminescence efficiency decreased almost exponentially due to thermal quenching (4.43 efficiency units-E.U. at 128 °C).

High-speed growth of CsSr1-xEuxI3 (x = 003, 005, 007) single crystals by the edge-defined film-fed growth method

CsSrI3:3%Eu (Φ10×55mm), CsSrI3:5%Eu (Φ10×50mm) and CsSrI3:7%Eu (Φ10×45mm) single crystals have been successfully grown by the edge-defined film-fed growth method for the first time, with the growth rate reaching 10-20mm/h. We designed a crystal growth device that achieved the first growth of this binary scintillation crystal by the EFG method. The raw material purification, temperature gradient of experimental device and growth rate, which are the effect factors of crystal quality, were systematically investigated. Moreover, the effect of Eu2+ concentration on optical properties were studied. The Eu2+ 5d-4f emission band was observed at 450-455nm, and the PL decay time was determined as 1.32µs for CsSrI3:3%Eu, 1.35µs for CsSrI3:5%Eu and 0.73µs for CsSrI3:7%Eu.

Europium concentration effects on the scintillation properties of Cs4SrI6:Eu and Cs4CaI6:Eu single crystals for use in gamma spectroscopy

Recently discovered scintillators Cs4SrI6:Eu and Cs4CaI6:Eu have shown promising properties for gamma-ray detection in homeland security applications, with <4% energy resolution (at 662 keV) and light yields above 50,000 ph/MeV. However, a thorough investigation of the effects of europium concentration has not yet been conducted. In this work, Eu2+ concentration was varied from 0.5 mol% to 9 mol%, and Ø7 mm single crystals were grown from the melt via the vertical Bridgman method. Scintillation performance was evaluated as a function of Eu2+ concentration to determine the optimal amount. The observed trend was improved energy resolution and higher light yield with increasing Eu2+ concentration up to 7 mol%. The best energy resolution achieved was 3.2% for Cs4SrI6:Eu 7% and 3.6% for Cs4CaI6:Eu 7%. Their respective light yields were 71,000 ph/MeV and 69,000 ph/MeV.

Absolute Luminescence Efficiency of Europium-Doped Calcium Fluoride (CaF2:Eu) Single Crystals under X-ray Excitation

The absolute luminescence efficiency (AE) of a calcium fluoride (CaF2:Eu) single crystal doped with europium was studied using X-ray energies met in general radiography. A CaF2:Eu single crystal with dimensions of 10 × 10 × 10 mm3 was irradiated by X-rays. The emission light photon intensity of the CaF2:Eu sample was evaluated by measuring AE within the X-ray range from 50 to 130 kV. The results of this work were compared with data obtained under similar conditions for the commercially employed medical imaging modalities, Bi4Ge3O12 and Lu2SiO5:Ce single crystals. The compatibility of the light emitted by the CaF2:Eu crystal, with the sensitivity of optical sensors, was also examined. The AE of the 10 × 10 × 10 mm3 CaF2:Eu crystal peaked in the range from 70 to 90 kV (22.22 efficiency units; E.U). The light emitted from CaF2:Eu is compatible with photocathodes, charge coupled devices (CCD), and silicon photomultipliers, which are used as radiation sensors in medical imaging systems. Considering the AE results in the examined energies, as well as the spectral compatibility with various photodetectors, a CaF2:Eu single crystal could be considered for radiographic applications, including the detection of charged particles and soft gamma rays.

Optically-stimulated luminescence properties of BaBr2:Eu translucent ceramic and single crystal

BaBr2:Eu (0.5 mol%) translucent ceramic has been synthesized using spark plasma sintering, and then the optical, scintillation and optically-stimulated luminescence (OSL) properties have been investigated. To evaluate the potential of translucent ceramics, BaBr2:Eu (0.5 mol%) single crystal has been grown by the vertical Bridgman–Stockbarger method for the comparison. When the thickness of the crystal and ceramic samples were fixed to approximately 0.5 mm, both the samples showed translucency in the visible light range. In the scintillation spectra, both the samples showed two emission peaks at around 400 and 500 nm, and the origin of the emissions were the 5d–4f transitions of Eu2+ and the F-VK center recombination, respectively. Regarding the OSL properties after x-ray irradiation, the OSL spectra of the samples showed an emission band peaking at around 400 nm, and the detection limit of the crystal and ceramic samples were 1 and 10 mGy, respectively.

Correlation of afterglow, trap states and site preference in RE2O3:1%Eu (RE = Lu, Y, Sc) single crystal scintillators

RE2O3:1%Eu (RE=Lu, Y, Sc) single crystals were grown by the optical floating zone method. Correlated measurements of afterglow curves, thermoluminescence, photoluminescence decay, and radioluminescence curves were performed. It is found that the afterglow intensity of Sc2O3:Eu is much lower than the other two compounds and Y2O3:Eu presents a slightly lower afterglow intensity than Lu2O3:Eu. It is discussed in the light of the influence of trap states and site preference in the RE2O3:Eu. The afterglow difference between Sc2O3:Eu and other two compounds mainly comes from the disappearance of Schottky defect in Sc2O3:Eu. Meanwhile the afterglow difference between Y2O3:Eu and Lu2O3:Eu probably ascribes to the lower S6 site ratio in Y2O3:Eu. Their photoluminescence and other radioluminescence properties were also measured and compared.

Magnetotransport Properties of Eu1−xLaxTiO3 (0 ≤ x ≤ 0.07) Single Crystals

The electronic phase change from an antiferromagnetic insulator to an antiferromagnetic/ferromagnetic-like metal has been investigated for the electron-doped EuTiO3, i.e., the single crystals of Eu...