Hexagonal Type Research Articles

Enhanced magnetocaloric effect in the Tb2In1−xAlx (0 ≤ x ≤ 0.6) alloy by hetero-structural alloying

The evolutions of the crystallographic structure and magnetic phase transition in Tb2In1−xAlx (0 ≤ x ≤ 0.6) alloys are investigated in this work. By gradually alloying antiferromagnetic orthorhombic Tb2Al, the crystalline structure of ferromagnetic Tb2In is gradually distorted from the hexagonal type for x ≤ 0.3 to orthorhombic one for x ≥ 0.4. The ferromagnetic ground state for x ≤ 0.4 is also gradually evolved into antiferromagnetic one for x ≥ 0.5. The phase transition temperature is decreased monotonously. At the critical composition of x = 0.4, the weak field-triggered metamagnetism is realized, leading into the enhanced maximum of magnetic entropy change from 6.6 J kg−1 K−1 in Tb2In to 10.6 J kg−1 K−1 in Tb2In0.6Al0.4 for a field of 5.6 × 106 A/m. The origin is supposed to be from the lattice distortion due to the critical composition at the phase borderline.

Dynamic Response of Metallic Foams Bumper with Morphology Design Variation in ABAQUS Software Simulation

Variation design of open-cell foams located in the bumper car were investigated in this paper. A brief experimental result on the dynamic response of crash was focused on energy absorption and deformation behavior. The bumper design was based on typical design of bumper compared with gradual density of hexagonal foam type. The method used was imitate crashing real behavior dynamic explicit using ABAQUS simulation software with some extra constraint, such as: crashing object and crash direction. Results showed the design strongly affect the value of energy absorption and deformation. Energy absorption was higher using hexagon foams compare to the normal bumper structure with 4.8740 E6 Joule and 4.8572 E6 respectively. Furthermore, highest energy absorption was by simulated redesign hexagon foam into varying thickness (gradual density) – similar to cortical bone structure – with 4.950 E6 Joule. Meanwhile the deformation shows highest value on typical design of bumper with 4 cm translation after crashed. Expected design has to be safe for passengers with have high ability to absorb energy and minimize the deformation movement.

Server processor heat sink analysis and modifications to improve its thermal performance

Heat generation in the electronic components of high-performance computing servers is a matter of concern. Heat generation adversely affects the performance of these servers, certain temperature limits are required for these server processors and other electronic components to work within suitable conditions. Furthermore, in order to improve CPU performance and functioning, the heat flux in today's processor packages is increasing day by day, even as server CPUs and other components shrink in size. The air-cooling technique is the most broadly utilized and efficient technique of the present accessible electronic cooling advances. In data centers, heat sinks with forced air are utilized to keep server processors and other electronic components cool. The cooling systems of electronic gadgets are a growing field of research. The aim of this work is to contribute to this research field by investigating the effects of inlet air properties on server processor heat sink thermal performance with a heat load of 140 W. The heat sink performance depends on various parameters. The influence of various geometries of lateral perforation on heat sink fin walls was numerically analysed in this study to improve the thermal performance of the server processor plate fin heat sink. The CFD Solver is used for analysing the performance of heat sink and the effect of lateral perforation shapes on heat sink fins. The three shapes of perforation are considered as square, circular, and hexagonal types, with the same cross-sectional area and pitch of inline arrangement. In comparison to plate fin heat sinks, the numerical results demonstrate that a laterally perforated finned heat sink has a lower base temperature and a low thermal resistance. The use of a perforated heat sink also saves material and reduces the weight of the heat sink.

On synthesis, stability and superconductivity of ThNb2H12under pressure: ab-inito calculations

Systematic study employing first-principle electronic structure method along with the evolutionary structure search algorithm as implemented in the universal structure predictor evolutionary Xtallography (USPEX) code has been carried out to look for the possibility of synthesising the ternary hydride (ThxNbyHz) from constituent's thorium, niobium and hydrogen. Our study suggests that the ternary hydride with formula ThNb2H12 will be globally stable above 12.5 GPa indicating the possibility of its formation from constituents Th, Nb, H and binary compounds of Th-H and Nb-H. Further, though the global stability of this compound is predicted to be beyond 12.5 GPa, it is metastable at 0 GPa. We have theoretically explored different formation routes to synthesize this compound. The zero-pressure monoclinic structure (Cm) of metastable ThNb2H12 undergoes a transformation to hexagonal structure (P6/mmm) at 3.5 GPa and this hexagonal structure (P6/mmm) transforms to other hexagonal type structure (P6/m) at 50 GPa. The high pressure structural sequence so predicted through static lattice calculations has been further substantiated by confirming the elastic and lattice dynamic stability of each structure in the pressure regime of their stability. Employing Allen–Dynes modified McMillan [P. B. Allen and R. C. Dynes, Phys. Rev. B 12, 905 (1975)] formula along with the fixed Coulomb pseudopotential of 0.1 and calculated electron-phonon coupling parameter, the superconductive temperature has also been calculated for this compound. Our analysis indicates that this material will behave as superconductor with transition temperature (Tc) ∼ 25 K at 15 GPa, which, will reduce to 4 K upon further compression to 100 GPa. Our analysis on lattice thermal conductivity of this compound in P6/mmm phase, at 15 GPa, shows a significantly large anisotropy in conductivity tensor, especially at lower temperatures.

Green hydrothermal synthesis of Ga doping derived 3D ZnO nanosatellites for high sensitive gas sensors

A green hydrothermal synthesis methodology is employed for the synthesis of Ga3+ doped ZnO 3D nanosatellite structures. XRD technique exposed the hexagonal wurtzite type crystal structure of the 3D Ga3+ doped ZnO nanostructures. Ga3+ induced 3D morphology evolution in accordance to Ga doping concentration is realized via. the FESEM images. The FESEM images indicated one sided capped rod like structures (50–250 nm) in pristine ZnO, whereas 3D satellite kind of morphology (>500 nm) was observed in 5% Ga3+ doped ZnO structures. TEM images revealed physical specifications of 3D nanosatellite structures exposing the central rod of 500 nm length & 250 nm in width and the branch rods grown vertical to the central rod of length 300 nm and width of 50 nm. Further, optical absorbance and photoluminescence spectra confirmed the electron rich state of ZnO with Ga3+ doping. The gas sensing performance has shown selectivity toward CO gas at a working temperature of 250 ⁰C. High CO sensing was recorded for 5% Ga3+ doped ZnO 3D nanosatellites with attractive sensing characteristics such as good response, fast response time & fast recovery time.

Lower rim functionalized bowl-shaped resorcin[4]arene with alkyl arms: A simplified approach to build supramolecular liquid crystals

Herein, a simple two step method was used to prepared bowl-shaped supramolecular mesogens based on resorcin[4]arene containing octa-substituted alkyl arms. The introduction of alkoxy tail group at their peripheries has different effect on the exhibition of the mesogenic behavior of the materials. These functionalized supramolecular compounds were investigated for their liquid crystalline properties and molecular self-assembly type behavior. The lower alkyl arm substituted supramolecules shows SmC type mesogenic properties while higher alkyl arm substituted compounds display columnar hexagonal type mesogenic properties. Thus, in the resorcinarene based materials, the role of alkoxy chain affects the transition temperature, including the self-assembly of the compounds. The prepared supramesogens are promising to stabilize the mesophase over a higher temperature range. The structure-property correlation is also discussed in the present study. This research suggest that the calix[4]resorcinarene core is a better candidate to fabricate supramolecular materials to achieve liquid crystalline properties with higher thermal stability. The structural confirmation and characterization of resorcinarene based compound has been characterized by using different analytical and spectroscopic techniques.

Nanoscale AgI-WO3 binary photocatalyst: Synthesis, brief characterization, and investigation of its photocatalytic activity

A novel AgI/WO3 binary system with good visible-light photocatalytic performance was fabricated and characterized by XRD, FTIR, SEM-EDX, X-ray map, photoluminescence (PL), and UV–Vis DRS techniques. A hexagonal wurtzite type β-AgI and monoclinic WO3 crystallites were detected. The average crystallite size of about 37.7 nm (by Scherrer formula) and 34.7 nm (by Williamson-Hall formula) was obtained for the binary catalyst. W–O–W and O–W-O vibrational modes showed intense absorption bands at 591, 761, and 828 cm−1 (or at 816 cm−1), and Ag-I around 595 and 640 cm−1 (that were broadened due to ionic future of AgI) in FTIR spectra. Absorption edge wavelengths of 506, 464, and 465 nm correspond to Eg-values of 2.45, 2.67, and 2.66 eV were estimated for AgI, WO3, and AgI/WO3 samples, respectively. PL spectra showed the most negligible intensity for the binary catalyst regarding the individual AgI and WO3 systems. PL intensity as a function of AgI: WO3 mole ratio of binary catalyst in two acetone and ethanol solvents was followed and good illustrated. The system with a mole ratio of 1:2 showed the lowest PL intensity and the highest photocatalytic activity. The peak intensity in ethanol as a higher polar solvent than acetone was increased. Synergistic photocatalytic activity of the proposed binary catalyst was observed toward methylene blue (MB) that depended on the AgI: WO3 mole ratio. The kinetics of the process obeyed the pseudo-first-order Hinshelwood model with k-values of 0.0123, 0.0216, and 0.0395 min−1 for WO3, AgI, and AgI/WO3 catalysts, respectively. The rate constant for the binary catalyst is 1.83 and 3.21 times greater than the values obtained for WO3 and AgI NPs, respectively. The Hinshelwood plot constructed based on COD data for the binary catalyst showed a rate constant of 0.0365 min−1, comparable with that obtained based on the photodegradation data.

Cadmium sulfide doped with silver as CO2 gas sensor using pyrolysis technique

<p>The monitoring of CO2 in our life safety, industrial, and chemical laboratory<br />applications make it an inspiring task. The chemical spray pyrolysis technique<br />was used to prepare CdS/Ag thin films. The nanocrystalline cadmium sulfide<br />thin films were doped with Silver at different doping concentrations (0%, 2%,<br />and 4%). The morphologies, structures, and gas sensing properties of CdS/Ag<br />films are presented. The samples were characterized using X-ray diffraction<br />(XRD) and atomic force microscope (AFM). The XRD results show that the<br />films are a polycrystalline composition and hexagonal type with a favoured<br />orientation along (111) direction. The average grain size (nm) of AFM is<br />between 75 and 55 nm. As a result, Ag doping changes the sensitivity of the<br />samples respectively with the percentage of doping with time. The synthesis<br />samples show controlling sensitivity and the small response of sensitivity are<br />the key point in this study.</p>

Analysis and characterization of tin-doped ZnO nanostructures

In this paper, undoped and tin-doped ZnO nanostructures were grown onto non-conductive substrates by a simple solution method. Structural, morphological, optical and electrical properties of the structures were investigated with respect to tin concentration. From XRD studies, all the ZnO nanostructures were found as hexagonal wurtzite type structures growing preponderantly oriented with c-axis nor- mal to the substrate. An increase in tin content resulted in a decrease in grain size, whereas the dislocation density in- creases. SEM observations indicated that all the structures were textured throughout the substrates without any cracks or pores. The influence of incorporation of tin on surface morphology of the samples was clearly seen. Average diameter of the nanostructures decreased with increasing tin content. Absorption spectra of the structures revealed that the band gap of the films increases with increasing tin concentration. It is found that the tin-doped samples have higher average transmittance than the undoped one. The 1 % tin-doped sample exhibited ∼80 % average transparency, which was the best transparency among the doped samples. Electrical measurements showed that resistivity of the structures increased with increasing dopant concentration. This increasing was attributed due to a decrease in carrier con- centration caused by carrier traps at the grain boundaries.

Unraveling the Complexity of Nano-Dispersoids in the Oxide Dispersion Strengthened Alloy 617.

Nanocrystalline oxides are mainly responsible for Ni-base oxide dispersion strengthened (ODS) superalloys excellent thermo-mechanical properties. To establish the microstructural correlations between the metallic matrix and various oxide dispersoids, we report here the atomic-scale structure and chemistry of the complex nano-oxide dispersoids. Ultrahigh-resolution Cs-aberration-corrected scanning transmission electron microscopy (STEM) based techniques have been used to resolve nano-dispersoids in the Alloy 617 ODS. These nano-oxides, interestingly, possess a variety of high-angle annular dark-field (HAADF) contrasts, that is, bright, dark, and bi-phases. Both the light and heavy atoms have been found to be present in Y–Al–O complex-oxide nanostructures in varying quantities and forming a characteristic interface with the metallic matrix. In overcoming the limitation of conventional STEM-HAADF imaging, the integrated differential phase-contrast imaging technique was employed to investigate the oxygen atoms along with other elements in the dispersoids and its interface with the matrix. The most intriguing aspect of the study is the discovery of a few atoms thick Al2O3 interlayer (shell) around a monoclinic Y–Al–O core in the Ni-matrix. On the other hand, when the dispersoid is a hexagonal type Y–Al–O complex, the interface energy is already low, maintaining a semi-coherent interface and it was devoid of a shell.

Crystal and electronic structures of a new hexagonal silicide Sc38Co144Si97

Sc38Co144Si97 was prepared from the elements by arc melting under argon and subsequent annealing at 800 ​°C for 350 ​h. Single-crystal X-ray diffraction reveals Sc38Co144Si97 to crystallize in a new hexagonal structure type: Pearson's symbol hP279, space group P63/m, a ​= ​33.624(7), c ​= ​3.639(1) Å. The crystal structure of Sc38Co144Si97 can be considered as a 2D intergrowth of three kinds of fragments of simpler structure types: hexagons and quadrilaterals with the arrangements of the Sc6Co30Si19-type and triangles with the arrangement of the Gd4Co13(Si, P)9-type. Quantum chemical calculations have been performed to analyze the electronic structure and provide deeper insight into the structure-property relationships. The Extended Hückel (EH) calculation indicates that Co in Sc38Co144Si97 adopts close to a d10 configuration owing to the covalent interaction with Si. The Sc–Co and Sc–Si interactions are more ionic, and Co–Co and Co–Si bonds are more covalent interactions.

Magnesium-rich intermetallic compounds RE 3Ag4Mg12 (RE = Y, La–Nd, Sm–Dy, Yb) and AE 3Ag4Mg12 (AE = Ca, Sr)

Abstract The magnesium-rich intermetallic compounds RE 3Ag4Mg12 (RE = Y, La–Nd, Sm–Dy, Yb) and AE 3Ag4Mg12 (AE = Ca, Sr) were synthesized from the elements in sealed tantalum ampoules through heat treatment in an induction furnace. X-ray powder diffraction studies confirm the hexagonal Gd3Ru4Al12 type structure, space group P63/mmc. Three structures were refined from single crystal X-ray diffractometer data: a = 973.47(5), c = 1037.19(5) pm, wR2 = 0.0296, 660 F 2 values, 30 variables for Gd3Ag3.82(1)Mg12.18(1), a = 985.27(9), c = 1047.34(9) pm, wR2 = 0.0367, 716 F 2 values, 29 variables for Yb3Ag3.73(1)Mg12.27(1) and a = 992.41(8), c = 1050.41(8) pm, wR2 = 0.0373, 347 F 2 values, 28 variables for Ca3Ag3.63(1)Mg12.37(1). Refinements of the occupancy parameters revealed substantial Ag/Mg mixing within the silver-magnesium substructure, a consequence of the Ag@Mg8 coordination. The alkaline earth and rare earth atoms build Kagome networks. Temperature dependent magnetic susceptibility measurements indicate diamagnetism/Pauli paramagnetism for the compounds with Ca, Sr, Y and YbII, while the others with the trivalent rare earth elements are Curie-Weiss paramagnets. Most compounds order antiferromagnetically at T N = 4.4(1) K (RE = Pr), 34.6(1) K (RE = Gd) and 23.5(1) K (RE = Tb) while Eu3Ag4Mg12 is a ferromagnet (T C = 19.1(1) K). 151Eu Mössbauer spectra confirm divalent europium (δ = −9.88(1) mm s−1). Full magnetic hyperfine field splitting (18.4(1) T) is observed at 6 K. Yb3Ag4Mg12 shows a single resonance in its 171Yb solid state NMR spectrum at 6991 ppm at 300 K indicating a strong, positive Knight shift.

Properties of fire-retardant vermiculite-concrete composite and fine-grained concrete for two-layer reinforced cement structures

Objective. Development of compositions of fire-retardant vermiculite-concrete composites for reinforced cement structures. Investigation of the properties of fire-retardant vermiculite-concrete composite and fine-grained concrete for two-layer reinforced cement structures.Method. Methods for increasing the fire resistance of reinforced concrete structures are considered. Research is focused on the development of fire-retardant composites using expanded vermiculite and volcanic ash. To improve the physical and mechanical properties of the fire-retardant composite, a mixture of Portland cement, gypsum, lime, basalt fiber, saponified wood resin, volcanic ash and expanded vermiculite has been developed. For the study of vermiculite concretes reinforced with basalt fiber, a second-order rotatable plan of the regular hexagon type was used.Result. Fiber-vermiculite concretes are proposed, which have improved fire-retardant properties compared to known compositions. This is due to the better preservation of the fiber-vermiculite-concrete layer when heated as a result of fiber reinforcement. Also, thanks to the addition of SDO, the fire-retardant properties of the composite increase due to the additional porosity of the fiber-vermiculite-concrete. The parameters of the "stress-strain" diagram of a vermiculite-concrete composite and fine-grained concrete have been obtained.Conclusion. Vermiculite concretes with an average density of 480-560 kg/m3 have the best fire-retardant properties. The developed two-layer reinforced cement structures have high fire resistance.

Analisis Stabilitas Artificial Reefs Tipe Hexagonal

In solving the problem of abrasion and also protecting marine ecosystems, it is necessary to come up with an idea, namely a wave energy retaining structure that is also capable of being a habitat for marine biota. Therefore, in this study, artificial coral reefs were tested which are considered capable to solv e these problems, plus those which at the same time rehabilitate damaged coral reef ecosystems. The artificial reefs model in this test is a hexagonal type with one layer arrangement. To get the success value (K D ) of artificial reefs, it is seen from the percentage of damage caused by the influence of height and wave period. Then the K D value was calculated using the Hudson formula so that it was found that the hexagonal type artificial reefs had a K D value = 1.2.

First-principles calculations to investigate the Electronic and Optical Properties of Hexagonal, Triclinic, and Monoclinic Structures of [formula omitted]-BiFeO[formula omitted

The electronic structures and optical properties of hexagonal (R3c), triclinic (P1), and monoclinic (R3) structures of the strongly correlated α-BiFeO3 (BFO) systems are presented by adopting a full-potential linearized augmented plane-wave method. For an accurate bandgap, the exchange–correlation functional called the corrected local density of Hubbard (LDA + U) method and modified Becke-Johnson (mBJ) exchange potential are used. We performed several theoretical calculations to investigate the electronic and optical properties of BFO with the R3c space group only. Therefore, this study focuses on elucidating the physical properties of other space groups such as P1 and R3 of BFO. This study obtained indirect bandgaps of 2.24 and 2.55 eV for R3c, 2.3 and 2.5 eV for P1, and 2.15 and 2.45 eV for R3 obtained by LDA + U and mBJ methods, respectively. Only the direct bandgap (2.44 eV) for R3c, acquired by the LDA + U, perfectly matches the experimental absorption measurement of single-crystal BFO (2.4 eV). For the mBJ potential, for all BFO structure types, the direct bandgaps are slightly larger than the indirect bandgaps. The LDA + U spectrum features of the imaginary part of the dielectric function for the hexagonal and triclinic structure types are in better agreement with the experimental findings than those of the mBJ method. Although the BFO structures have indirect and direct bandgaps, the direct optical absorption of the LDA + U was not significant for the R3 structure. Although the mBJ method is highly efficient compared to the most accurate GW method, it is time-consuming compared to the LDA + U method. Therefore, LDA + U is considered inexpensive and more reliable than mBJ in better understanding optoelectronic properties. It is, therefore, preferable to use the LDA + U method for BFO electronic structural calculations to reduce the calculation time and obtain a better description of the bandgaps and some physical properties, particularly optical properties.

Computational prediction of new stable superconducting magnesium hydrides at high-pressures

Because of its potential use for technological applications, realization of high-temperature superconductivity is one of the greatest goals of physics. In particular, if superconductivity at (or near) room-temperature is realized, it can dramatically revolutionize technology which can benefit the daily life of mankind. One of the methods which received particular attention to scientists is to compress dense-hydrogen containing compounds at high-pressures. In this paper, we explored new stable superconducting magnesium hydrides by using first-principle calculations. Using the open source quantum ESPRESSO software package, we report new stable phases of magnesium hydrides. We studied magnesium hydrides with different structures; and we found that, next to the previously predicted tetragonal (I4/mmm) type MgH4, another MgH4 with P63/mmc (hexagonal) type symmetry also show an estimated superconducting temperature up to 280 K at a pressure of about 301 GPa. After carefully analyzing the electronic band structure, density of electronic states, and other properties of each structure, we calculated the superconducting temperature, electron-phonon coupling constant, Eliashberg spectral function, and other vibrational properties of each predicted structure. Our calculated values are consistent with experimental observations.

From affine A4 to affine H2: group-theoretical analysis of fivefold symmetric tilings.

The projections of lattices may be used as models of quasicrystals, and the particular affine extension of the H2 symmetry as a subgroup of A4, discussed in this work, presents a different perspective on fivefold symmetric quasicrystallography. Affine H2 is obtained as the subgroup of affine A4. The infinite discrete group with local dihedral symmetry of order 10 operates on the Coxeter plane of the root and weight lattices of A4 whose Voronoi cells tessellate the 4D Euclidean space possessing the affine A4 symmetry. Facets of the Voronoi cells of the root and weight lattices are identified. Four adjacent rhombohedral facets of the Voronoi cell V(0) of A4 project into the decagonal orbit of H2 as thick and thin rhombuses where long diagonals of the rhombohedra serve as reflection line segments of the reflection operators of H2. It is shown that the thick and thin rhombuses constitute the finite fragments of the tiles of the Coxeter plane with the action of the affine H2 symmetry. Projection of the Voronoi cell of the weight lattice onto the Coxeter plane tessellates the plane with four different tiles: thick and thin rhombuses with different edge lengths obtained from the projection of the square faces and two types of hexagons obtained from the projection of the hexagonal faces of the Voronoi cell. The structure of the local dihedral symmetry H2 fixing a particular point on the Coxeter plane is determined.

Nano 5% Fe–ZnO: A highly efficient and recyclable heterogeneous solid nano catalyst for the Biginelli reaction

In this paper, we report the synthesis and catalytic application of 5% Fe–ZnO nanocatalyst for the synthesis of 3,4-dihydropyrimidin-2-one derivatives as a highly efficient heterogeneous nanocatalyst. The structural and morphological features of the synthesized nanocatalysts were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Using Debye-Scherer's formula, the average particle size for undoped ZnO was calculated to be 24.55 nm, while the average particle size for 5% Fe–ZnO was calculated to be 22.37 nm. The high resolution transmission electron microscopy (HR-TEM) revealed a hexagonal crystal lattice type. The Brunauer–Emmett–Teller (BET) surface area of ZnO and 5% Fe–ZnO was found to be 56.50 m2/g and 72.65 m2/g, respectively. Energy Dispersive X-Ray Analysis (EDX) confirmed the elemental composition of undoped ZnO and doped 5% Fe–ZnO nanocatalysts. Biginelli products were produced using a one-pot three-component reaction of urea, β-dicarbonyl compound, and various aromatic aldehydes using 5% Fe–ZnO under clean conditions. It was found that a 5% Fe–ZnO nanocatalyst is a highly efficient heterogeneous nanocatalyst for the synthesis of 3,4-dihydropirimidinones. 1H NMR and 13C NMR analysis was used to confirm the structure of the synthesized Biginelli adducts. This synthetic protocol offers several advantages, including a short reaction time and purity of the synthesized, reusability and ease of catalyst separation, and a clean and quick workup.

Effect of repair parameters on composite plates under low velocity impact

In this study, the impact behavior of patch-repaired layered composite plates under low velocity impact loads was numerically investigated. For this purpose, layered composite plates with holes with different geometries in the middle were repaired with patches using various adhesives. Impact behavior of the composite material was investigated by dropping the strikers with different speeds on the repaired composite plate. Layered composite plate was used as the sheet and patch material, and the orientation angles are [0 ° / 45 ° / 45 ° / 0 °] for the plate and [0 ° / 45 °] for the patch. ANSYS Ls-Dyna finite element package program was used for three dimensional modelling and solution. Therefore, the effects of variables such as striker, adhesive, plate and patch on the impact behavior of layered composite material were investigated for different boundary conditions. It has been determined that the hexagonal patch type performs better than other patch geometries.

Behavior of implant and abutment sets of three different connections during the non-axial load application: An in vitro experimental study using a radiographic method

During the masticatory cycle, loads of different intensities and directions are received by the dental structures and/or implants, which can cause micromovements at the junction between the abutment and implant. The objective of this in vitro study was to evaluate the behavior of three different implant connections subjected to different load values using a digital radiography system. Additionally, the torque values for removing the abutment screws were also measured and compared. Ninety sets of implant and abutment (IA) were used, divided into three groups according to the type of connection (n =30 per group): EH group, external hexagon type connection; IH group, internal hexagon connection; and, MT group, Morse taper connection. MT group showed the better vertical misfit behavior at the three intensity of load applied, in comparison with EH and IH groups. In the analysis of torque maintenance (detorque test), MT group showed higher values of detorque when compared with the measured values of EH and IH groups (p <0.001). The IA sets of EH and IH groups showed a microgap in all levels of applied loads, unlike the MT group this event was not observed. In the detorque test, MT group increase in the torque values when compared to the initial torque applied, unlike EH and IH groups showed a decrease in the initially torque applied in all conditions tested. A positive correlation was detected between the misfit and detorque values.