Navegando por Autor "Franco Júnior, Adolfo"
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Item Bifunctional magnetic luminescent particles based on iron oxide nanoparticles grafted with a europium silylated bypiridine tris(β-diketonate) complex(2016) Silva, Robson Rosa da; Duarte, Adriana Pereira; Sábio, Rafael Miguel; Caiut, José Maurício Almeida; Gressier, Marie; Menu, Marie-Joëlle; Franco Júnior, Adolfo; Ribeiro, Sidney Jose LimaA new highly magnetic-luminescent nanocomposites has been synthesized by grafting luminescent europium complex comprising tris(b-diketone) and bypridine ligand modified with a silylil function group (Eu[(TTA)3(Bpy-Si)] complex) on the surface of superparamagnetic iron oxide nanoparticles with 11 nm in size coated with a thin silica outer layer. The γ-Fe2O3/SiO2 nanoparticles were fully characterized by ATR-FTIR, FE-SEM, HR-TEM and magnetic measurements to confirm the structure of nanocomposite and the superparamagnetic behavior. Grafting with europium silylated bypiridine tris(β-diketonate) complex on nanoparticles surface was achieved by covalent bonding through triethoxysilyl groups which allows high concentration of the luminescent species. The resulting nanocomposite display superparamagnetic profile and the indirect excitation in the ultraviolet region outcomes high red luminescence intensity (at 613 nm) with narrow characteristic emission lines of Eu(III) and emission lifetime in the millisecond range. The nanocomposite is potentially useful for applications as biolabelling, imaging, bio-separation and bioassays.Item Cation distribution of ZnxCo1-xFe2O4 nanoparticles: a resonant X-ray diffraction study(2020) Nakagomi, Fábio; Souza, Paulo Eduardo Narcizo de; Castro, Tiago de Jesus e; Garg, Vijayendra Kumar; Oliveira, Aderbal Carlos de; Silva, F. C. e; Franco Júnior, Adolfo; Morais, Paulo Cesar de; Silva , Sebastiao William daIn this study, it was successfully explored the use of resonant X-ray diffraction, with energies tuned to the absorption edges of Zn2þ, Fe3þ and Co2þ, as an innovative approach to obtain the structural properties of the as-synthesized ZnxCo1-xFe2O4 nanoparticles (NPs) (0.0 x 1.0). Zinc-cobalt ferrite, which has potential application in magnetic recording, photo-magnetic devices, biomedicine, gas sensing, catalysis, etc., was synthesized by solution combustion method and analysed by X-ray diffraction, Raman and Mossbauer spectroscopies. Rietveld re € finement shows that all samples present single-phase cubic spinel structure (space group Fd3m) with lattice parameter increasing linearly with the Zn-content (x), from 8.37 Å to 8.43 Å. The data also showed that the average diameter of the crystallites sets around 45 nm and do not depend on the Zn-content. In addition, a complete cationic distribution between A- and Bsublatices was obtained by resonant X-ray diffraction and compared with the partial cationic distribution obtained by Raman and Mossbauer spectroscopies. A strong correlation between the data was found. € Despite evidences of the presence of Fe3þ-ions in both crystallographic sites, it was found that as the Zncontent increases, Zn2þ-ions tend to preferentially occupy A-sites, forcing Fe3þ-ions to occupy B-sites. As results, it was observed that with increasing Zn-content, the average distance between cations and anions increases in A-sites (from 1.88 Å to 1.98 Å) and decreases in B-sites (from 2.06 Å to 2.03 Å). Resonant X-ray diffraction and Mossbauer data indicate that the replacement of Co € 2þ- by Zn2þ-ions changes substantially the NPs’ hyperfine parameters, suggesting that the NPs with intermediate Zncontent present lower crystalline quality while compared to the samples with x ¼ 0.0 and x ¼ 1.0. Evidence of symmetry reduction (from m3m to 3m) in the B-sites was obtained, which is in accordance with the variation verified in the integrated areas and energies found for the Raman modes below 600 cm1 . Finally, the excellent agreement between the results obtained by resonant X-ray diffraction, Raman spectroscopy and Mossbauer spectroscopy indicate the robustness of the approach herein used to € assess the cation distribution in quaternary spinel ferrites.Item Colossal dielectric permittivity in Co-doped ZnO ceramics prepared by a pressure-less sintering method(2018) Pessoni, Hermínia Veridiana dos Santos; Banerjee, Prasun; Franco Júnior, AdolfoDielectric properties and impedance spectroscopic studies of single phase Zn1− xCoxO (0 ≤ x ≤ 0.05) ceramics, synthesized by a pressure-less solid state reaction method, have been carried out to investigate the origin of colossal dielectric permittivity (CP), ε′ ∼ 105, in a wide frequency (2 × 101–2 × 106 Hz) range. These results show that a defect density within the grain is present in the materials due to the use of pressure-less sintering at high temperature for a long duration of time. The colossal dielectric response is essentially due to this electronic inhomogeneous conduction mechanism within the material due to the production of absorption current in the thin grain boundary region which accumulates charge at the interface and induces Maxwell–Wagner interfacial polarization. Moreover, this defect structure further increases with the addition of Co ions and enhances the CP property. An effective way to control the colossal dielectric properties is to control the defect density within a grain by using a proper sintering method.Item Competitive effect of dopants on magnetic and structural properties in yttrium iron garnet co-doped with Er and Cr(2020) Leal, L. R. F.; Milani, Raquel; Oliveira, D. M.; Guerra Dávila, Yuset; Padrón Hernández, Eduardo; Franco Júnior, Adolfo; Viana Neto, Bartolomeu Cruz; Santos, F. E. P.; Pena Garcia, Ramón RaudelIn the present work, we have studied the competitive effect of Er and Cr dopants on the structural and magnetic properties of yttrium iron garnet (YIG) nanoparticles synthesized by the sol gel method. The YIG single phase was obtained for all samples and the variations of structural parameters were associated to the dopants influence. Fourier transform infrared spectroscopy showed typical absorption peaks of YIG, with small displacements for larger wavenumbers corresponding to vibrational modes (Fe–O) belonging to the tetrahedral sites. The behavior of the Raman vibrational modes as a function of dopant concentration confirms the insertion of Er in dodecahedral sites and Cr in the octahedral and tetrahedral sites. A frequency shifting of some Raman modes was observed as the Cr concentration increased. The powder morphology was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), evidencing agglomerated particles with irregular shapes. The Er and Cr incorporation in YIG promote random fluctuations in the saturation magnetization, coercivity and the magnetocrystalline anisotropy constants of the synthesized compound.Item A comprehensive study of Co1−xNixFe2O4 nanoparticles fabricated via three different synthetic methods(2019) Pessoa, Marcio Solino; Moscon, Paulo Sérgio; Melo, R. S.; Franco Júnior, Adolfo; Morais, Paulo Cesar deWereport on three different synthetic methods for producing Co1−xNixFe2O4 nanoparticles (x=0.0, 0.4, and 1.0): combustion (C), hydrothermal (HT), and forced hydrolysis (FH). Theoretical fittings of the ferromagnetic resonance (FMR) lines were achieved by considering a proposed four-fold symmetry model for randomly dispersed magnetic nanoparticles (NPs). The average grain size (D), between 10 and 80 nm, and magnetic properties are found to depend strongly on both the selectedsynthesis route and stoichiometry (x). Interestingly, while the HT- and FH-methods provide NPs with no systematic dependence of coercive field and remanence, upon x or D, the C-method showedmonotonic dependence. The magnetocrystalline anisotropy field (Ha), extracted from simulating theFMRspectra, systematically reduces with increasing x, regardless the synthetic route used. Worth mentioning that the largest (smallest) variation inHa is observed for the C-method (HTmethod) equals toΔHa=−3853 Oe (ΔHa=−1676 Oe).Item Dielectric and magnetic properties of three-layers laminated ceramic composite, K0.5Na0.5NbO3/CoFe2O4/K0.5Na0.5NbO3(2018) Franco Júnior, Adolfo; Banerjee, Prasun; Lima, Rodrigo José da SilvaThree-layers laminated ceramic composite system of K0.5Na0.5NbO3/CoFe2O4/K0.5Na0.5NbO3 (KCK) were prepared by conventional solid state reaction method. SEM analyzes revealed negligible inter-diffusion of chemical elements along the boundary layers in the laminated ceramic composite, KCK. The relative dielectric permittivity of the sandwiched ceramic composite was investigated in a broad frequency range, 101 –106 Hz at room temperature. The real part of the relative dielectric permittivity of KCK was strongly frequency dependent; being ∼ 1250 and ∼ 700 for 100 and 1 KHz, respectively. Also the dielectric study showed a deviation of Cole–Cole relaxation in CoFe2O4 and KNa0.5NbO3 materials to Maxwell–Wagner relaxation in the KCK. It was found that the magnetic properties such as saturation magnetization (Ms ∼ 77 emu/g), remanent magnetization (Mr ∼ 12 emu/g) and coercive field (Hc ∼ 320 Oe ) of KCK were quite the same as ferrimagmetic spinel bulk cobalt ferrite at room temperaturItem Effect of composition induced transition in the optical band-gap, dielectric and magnetic properties of Gd doped Na0:5Bi0:5TiO3 complex perovskite(2018) Franco Júnior, Adolfo; Banerjee, Parag; Romanholo, P. L.The optical band-gap, dielectric and magnetic properties of gadolinium doped sodium bismuth titanate ceramics, Na0:5Bi0:5 xGdxTiO3 (NBT:xGd) with x ¼ 0; 0:005; 0:01; 0:015 and 0:02, sintered by the conventional solid-state reaction were studied at room temperature. The X-ray diffraction (XRD) patterns revealed that the doping with Gd3þ 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 ¼ 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 Gd3þ ions changed the diamagnetic behavior in NBT samples to paramagnetic in the NBT:xGd ceramics.Item Effect of ferrite phase addition on the functional properties of (K0.5Na0.5)NbO3ceramics(2019) Lima, Rodrigo José da Silva; Banerjee, Prasun; Araújo, Eudes Borges de; Franco Júnior, AdolfoLead-free ceramics consist of ferroelectric K0.5Na0.5NbO3 (KNN) and spinel ferrimagnetic CoFe2O4 (CFO) phases were prepared by the conventional solid state reaction method. The constituent phase presence of multiferroic material was confirmed by X-ray diffraction techniques with Rietveld refinement methods. A systematic study of dielectric properties at room temperature with frequency revealed that the dispersion is in accordance with the Cole-Cole model with the presence of dc conductivity at lower frequencies. The main reason for this type of dispersion was related with the different heterogeneous conduction mechanism between the ferroelectric and ferrite phases in multiferroic structures. Complex impedance analysis re-established non-Debye type dielectric relaxation mechanism in the multiferroic. The effect of constituents phase variation on the electric and magnetic hysteresis behavior was also examined. The ferroelectric order diluted with the addition of ferrite content. The remnant magnetization (Mr) and saturation magnetization (Ms) values increased while the coercivity (Hc) values of the materialss decreased with the addition of ferrite content. We established that this material is a room temperature multiferroic and highlighted a possible way to modulate functional properties of this lead-free materials for application in microelectromechanical system (MEMS) technology.Item Effect of Gd doping on the structural, optical band-gap, dielectric and magnetic properties of ZnO nanoparticles(2017) Franco Júnior, Adolfo; Pessoni, Hermínia Veridiana dos SantosNanostructured Zn Gd O 1−x x δ (0 ≤ ⩽ 0.0 x 2) powders were synthesized by the combustion reaction method (CR) with the purpose to investigate the effect of Gd doping on the structural, optical band-gap, dielectric and magnetic properties at room temperature. The structure and morphology of all samples were characterized by X-ray diffraction (XRD), and transmission electron microscope (TEM). The XRD patterns of all samples exhibited sharp and intensive peaks of hexagonal wurtzite structure of ZnO without any evidence of spurious crystalline phases. The nanoparticles crystalized in roughly spherical morphology with bimodal particle size distribution centered at ∼30, ∼100 and ∼70, ∼160 nm for undoped and Gd – doped ZnO (x=0.02), respectively. Diffuse reflectance spectrum of each sample was obtained by using a UV/VIS/Near spectrometer and the optical band-gap, Eg, values decreased with increasing Gd doping concentration; being ∼3.23, and ∼3.17 eV for x=0 and 0.02, respectively at room temperature. This red shift on the band-gap was discussed in terms of new band levels below the conducting band. Also, the dielectric permittivity data of all samples could be evaluated by the Cole– Cole model. Seems that both oxygen vacancies (VO) or/and interstitial oxygen (O″¨ı) defects present in the Gd – doped ZnO samples play an important rule in the dielectric permittivity at room temperature. Furthermore, all Gd – doped ZnO samples exhibited typical paramagnetic behavior at rom temperatureItem Effect of Gd3+ ion on the structural and magnetic properties of (Nb and Al) co-doped rutile TiO2 single crystal(2021) Pessoni, Hermínia Veridiana dos Santos; Oliveira, Felipe Souza Oliveira; Faria, L. S. de; Machado, Antonio Jefferson da Silva Machado; Franco Júnior, AdolfoIn this study we investigated the influence of Gd3+ ions on the structural and magnetic properties of (Nb + Al) codoped TiO2 single crystals with nominal composition Ti0.995(Nb0.667Al0.333)0.005O2 (TNA) and Ti0.995(Nb0.667(Al0.1665Gd0.1665))0.005O2 (TNAGd) grown in an optical traveling floating zone (TFZ) furnace. The crystal structure and phase purity investigated by X-ray diffraction (XRD) and High resolution transmission electron microscopy (HRTEM) images of selected area electron diffraction (SAED) patterns confirmed the rutile crystal nature for both TNA and TNAGd samples. The magnetic properties were studied from 3 to 400 K in magnetic fields up to 60 kOe. ZFC/FC curves revealed paramagnetic behavior for TNA sample, while the presence of Gd3+ ions in the crystal structure drastically affected the magnetic properties turning to ferromagnetic behavior. The isothermal magnetization, M(H) curves for TNAGd samples were analyzed by the bound magnetic polaron (BMP) model. At the lowest temperature the values of the total moment of BMP’s (M0), spontaneous moment of a single BMP (ms), and the concentration of BMP’s (N) were found to be 1.58 emu/cm3, 840 μB, and 3.2 × 1019BMP/cm3, respectively. The number of Gd3+ ions per BMP was ̃113 and 75% of Gd3+ ions were inside the BMP’s and the remaining 25% were outside but diluted in the matrix or interacting antiferromagnetically.Item Effect of particle shape and size on themorphology and optical properties of zinc oxide synthesized by the polyol method(2018) Alves, Thiago Eduardo Pereira; Kolodziej, Charles; Burda, Clemens; Franco Júnior, AdolfoIn this study we prepared zinc oxide (ZnO) nanoparticles using the polyol method with zinc acetate and/or sodiumacetate in a propylene glycolmediumwith varied hydrolysis reaction time (10, 60 and 300min). Itwas observed that the hydrolysis reaction time and the concentration of acetate ions had a strong effect on the morphology and size of ZnO nanoparticles (NPs). X-ray diffraction (XRD) patterns revealed that all samples crystalized in the typical ZnO wurtzite structure and Rietveld refinement was used to characterize the structure and to suggest a preferential growth. Fourier transformed infrared spectroscopy (FTIR) was performed and showed the typical ZnO band, no impurity signals, as well as differences in A1 and E1 vibrationmodes due to different crystal growth in the structure. Raman scatteringwas carried out to determine the defects in the structure of ZnO, such as interstitial oxygen and oxygen vacancies. Transmission electron microscope (TEM) images revealed that ZnO NPs size and shape are strongly dependent on the hydrolysis reaction time and addition of acetate counter ions, respectively. The change in shape and size has also affected the optical properties, such as the optical bandgap (Eg) of ZnO NPs and their florescence.Item Effect of the synthesis method and calcination temperature on the formation of Ni–NiO nanocomposites(2019) Silva, R. B. da; Pinto, Rômulo Augusto de Oliveira; Soares, João Maria; Franco Júnior, Adolfo; Corrêa, Marcio Assolin; Bohn, Felipe; Costa, José Alzamir Pereira daWe investigate the structural, morphological, chemical, and magnetic properties of Ni–NiO nanocomposites synthesized through two distinct routes, sol–gel and coprecipitation, followed by calcination. By considering several techniques we show that the resulting nanocomposites, as well as their properties, are strongly dependent on both, synthesis method and calcination temperature. Hence, we explore the possibility of tailoring the physical properties of the nanocomposite by modifying production parameters. The results place the employed routes as a simple, low-cost candidate to the production of Ni–NiO nanocomposites, especially nickel oxide.Item Effects of defect dipoles on the colossal permittivity of ambipolar co-doped rutile TiO ceramics(2020) Lira, Stefane Oliveira de; Silva, Raphael Lucas de Sousa e; Banerjee, Parag; Franco Júnior, AdolfoThis study investigated the colossal permittivity of ambipolar co-doped rutile TiO2 ceramics obtained using the solid state sintering method for use as alternatives to high-performance dielectric materials. Ambipolar co-doping was conducted with compositions comprising Ti0:995ðNb1:33ðAl1 xCrxÞ0:666Þ0:005O2, where x ¼ 0, 0.3, 0.5, 0.7, 0.9, and 1. Analysis based on X-ray diffraction, Fourier transform-infrared spectroscopy, and Raman spectra showed that the dopants did not alter the crystal structure of rutile but they created some distortion in the TiO2 lattice. Analysis of the dielectric properties showed that the ceramics exhibited relatively low loss with colossal permittivity at room temperature. The existence of an asymmetrical relaxation mechanism was demonstrated with the Fuoss–Kirkwood dielectric model. The combined functions of defect dipoles and localized electrons were investigated for ambipolar co-doped TiO2 ceramics for use in high-density RAM and microelectronics applications.Item Effects of temperature and atomic disorder on the magnetic phase transitions in ZnO nanoparticles obtained by sol–gel method(2018) Pena Garcia, Ramón Raudel; Guerra Dávila , Yuset; Farias, B. V. M.; Martinez Buitrago , Davian; Franco Júnior, Adolfo; Padrón Hernández, EduardoIn this work, we have studied the effects of temperature and atomic disorder on the magnetic phase transitions in ZnO nanoparticles obtained by sol–gel method. The samples were sintered at temperatures of 600 C, 800 C 1000 C and 1200 C for 2 h. The X-ray diffraction (XRD) analysis have shown a single phase, belonging to the hexagonal structure of ZnO and the Rietveld refinement showed an increase in the lattice parameters a and c with increasing sintering temperature. The crystallite mean size (D) increases from 61 nm to 70 nm, while the lattices strain decreases from 0.181% to 0.169% when the sintering temperature varies from 600 C to 1200 C. The magnetic measurements at 300 K, exhibit a ferromagnetic contribution in combination with a paramagnetic component for samples obtained at 600 C, 800 C and 1000 C. A magnetic transition was verified for the sample obtained at 1200 C, now with diamagnetic behavior. The sol–gel method is presented as an alternative to study the evolution of the different magnetic phases as a function of the degree of atomic disorder in ZnO nanoparticlesItem Effects of Y and Ni co-doping in Bi2Fe4O9 - BiFeO3 based multiferroic ceramics(2021) Banerjee, Prasun; Franco Júnior, Adolfo; Ren, Zheng XiaoHere we reported the structural, microstructural and magnetic properties of BiFeO3 (BFO) and Bi0.99Y0.01Fe0.98Ni0.02O3 (BYFNO) ceramics modified with mullite type Bi2Fe4O9 multiferroic. The XRD results in such unmodified and modified ceramics suggested that the rhombohedral structure was distorted due to the doping where as the modification has an impact on the microstrain parameters. Micro-structural studies clearly showed the growth of average grain size due to the modification in the BFO ceramics. The presence of Bi2Fe4O9 on BYFNO ceramic caused an increment in the saturation magnetization up to 0.027 μB /f.u. The origin of such properties has been demonstrated on the basis of size effect, nature of the dopants and modification done in the ceramic systems.Item Enhanced dielectric and magnetic properties in multiferroic Bi Y Fe Ni O 0.99 0.01 0.99 0.01 3 ceramic(2016) Banerjee, Prasun; Franco Júnior, AdolfoAn enhanced low-frequency dielectric constant, ( ε′ ∼ 104), and ferromagnetic behavior at room temperature were observed in Bi Y Fe Ni O 0.99 0.01 0.99 0.01 3 (BYFNO) ceramic sintered by a modified solid state reaction method. The anti-ferromagnetic (AFM) nature of BiFeO3 (BFO) changed to ferromagnetic (FM) with saturation magnetization, Ms, and coercivity Hc values of ∼0.03 / . . μ f u B and ∼250 Oe, respectively at room temperature. The XRD patterns revealed that the co-doping of + Y3 and + Ni 2 ions at the A− and B− sites of BiFeO3 (BFO) resulted in a rhombohedrally distorted perovskite structure. This result was discussed in terms of the modification of the cycloidal spin structure, presence of + Ni 2 carriers and preservation of oxygen vacancy during the sintering process. This enhanced properties entitle the Bi Y Fe Ni O 0.99 0.01 0.99 0.01 3 one of the few multiferroic materials that exhibits both significant ferromagnetic and dielectric behaviors at room temperature.Item Enhanced dielectric permittivity on yttrium doped cobalt ferrite nanoparticles(2017) Franco Júnior, Adolfo; Pessoni, Hermínia Veridiana dos Santos; Alves, Thiago Eduardo PereiraNanoparticles (NPs) of CoYxFe2 xO4 (06 x 0:04) were synthesized by combustion reaction method in order to study the effect of Y3þ ions (x) on the dielectric properties. It was found that the relative dielectric permittivity (e0 ) measured in a broad range frequency 100–2 MHz at room temperature. e0 increases with the Y3þ ions concentration and decreased with frequency, being 200 (83), and 998 (320) at 100 Hz (1KHz) for x ¼ 0 and x ¼ 0:04, respectively. The experimental data could be fitted to the Cole–Cole model and the relaxation time (s) was found to increase with Y3þ ions concentration. The results were discussed in the terms of space charge polarization and ions distribution over tetrahedral A-site and octahedral Bsites of the spinel structure and cation vacancies due to the presence of Y3þ ions in the spinel structure of cobalt ferrites.Item Enhancing the electrical properties of NBT ceramics by the addition of small amounts of Yb(2021) França, E. L. T.; Romanholo, Pedro Victor Valadares; Simões, Simone da Silva; Falcão, Eduardo Henrique Lago; Franco Júnior, Adolfo; Machado, Fernando Luis de AraújoItem Functional properties of donor- and acceptor-co-doped high dielectric constant zinc oxide ceramics(2019) Silva, Raphael Lucas de Sousa e; Banerjee, Prasun; Franco Júnior, AdolfoIn this work we investigated the functional properties of a set of acceptor (Cu1+) and donor (Gd3+) codoped wurtzite ZnO ceramics Zn(1−x)(CuzGdy)xO for x = 0.01 synthesized by the pressure-less solid state sintering method. XRD and optical measurements established the substitution of dopant ions into zinc lattice sites directly. The co-doping process influenced the creation of oxygen vacancies which modified their electronic properties and decreased the band gap energy. The existence of such defects leads to non-radiative decay, which caused different electronic recombination in the luminescence emission. The samples exhibited a high dielectric constant (>= ∼103) with an acceptable low dielectric loss (tan δ ∼ 10−1) in the frequency range 10–103 Hz. The dielectric results were discussed in terms of different polarization effects that may be present in the lattice such as polaron-like electron transport/hopping, defect dipoles, and barrier layer capacitance effects. The presence of both donor (Gd3+) and acceptor (Cu1+) ions in ZnO decreased the dielectric loss in the materials and the most favorable balance between high dielectric constant and low dielectric loss properties was found. Impedance analysis ruled out any contribution from electrode–grain interfaces to the high-K (high dielectric constant) properties in pure and doped zinc oxide ceramics. The correlation between the physical properties studies are a guideline in the classificatory understanding of semiconductor materials.Item Functional properties of Ho3+ substituted cobalt ferrite in the context of the reduced mass model(2019) Pessoni, Hermínia Veridiana dos Santos; Alves, Thiago Eduardo Pereira; Banerjee, Prasun; Franco Júnior, AdolfoSpinel CoFe2−xHoxO4 were synthesized with forced hydrolysis technique. The presence of constituent phases and particle growth was determined by XRD technique with Rietveld refinement and HRTEM fitted with EDS method. The strain effect due to the Ho3+ substitution was visible in the FTIR spectrum analysis. The increment of the reduced mass due to the holmium doping resulted in a decrease of the band gap energy. Systematic frequency domain dielectric characterization showed that the relaxation mechanism in accordance with the Cole-Cole model at room temperature. We instituted here the probable way to modulate the functional properties with a reduced mass model to produce next-generation energy-saving spintronics and straintronics devices.
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