Article
Materials Science, Ceramics
Young-Il Kim, Maxim Avdeev
Summary: Perovskite lattice was modified with site vacancies and mixed anion composition to create Sr0.83Li0.17Ta0.83O1.88N0.74 (Li02N), which was further transformed into Sr0.83Li0.17Ta0.83O3 (Li02O) with optimized treatment. Both Li02N and Li02O showed Arrhenius behavior of ionic conductivity with different activation energies, suggesting that the nitride component enhances ionic conduction while anion lattice vacancies have the opposite effect.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Lingfang Zou, Zhuan Li, Zonglong Gao, Fu Chen, Wenjie Li, Yong Yu, Yimin Li, Peng Xiao
Summary: This study investigates the impact of Pr3+ doping on the ferroelectric properties of PZT ceramics, showing that it can improve piezoelectric activity and optimize performance stability. Introducing Pr3+ leads to a dense and fine microstructure, with an ideal coexistence of rhombohedral and tetragonal phases observed in the PPZT4 samples.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Jiaxin Gong, Jiheng Li, Xiaoqian Bao, Ruifen Hou, Xuexu Gao
Summary: The crystal structure and magnetic structure of Tb-Dy-Fe compounds were studied before and after annealing heat treatment, revealing the existence of tetragonal and rhombohedral phases at room temperature. The volume proportion of the hexagonal phase increased after heat treatment, and the effect of structural distortion on the magnetostriction of Tb-Dy-Fe was discussed based on analytical results.
Article
Materials Science, Multidisciplinary
Randeep Kaur, Anumeet Kaur
Summary: A solid state reaction technique was used to synthesize a series of solid solution materials, and their structures were analyzed using X-ray diffraction and Raman spectroscopy. The experimental results showed that these samples all exhibited ferroelectric and magnetic characteristics at room temperature, with specific phase transition temperatures. The impedance and modulus analysis revealed the contributions of bulk and grain boundaries in the samples, and conductivity relaxation was observed in all samples.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Kenji Iwase, Shuhei Ishida, Takashi Ueno, Kazuhiro Mori
Summary: This study investigated the residual hydrogen occupation mechanisms in MgZn2-type and CaCu5-type cells during the hydrogen absorption-desorption process. The results revealed the structural changes and deuterium occupation in NdNi3Dx and provided insights into the preferred deuterium sites in different cell types.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Carla Isabel Pinilla Ducreux, Ahmed A. Saleh, Azdiar A. Gazder, Elena Pereloma
Summary: The deformation behavior of a metastable beta Ti-10V-2Fe-3Al alloy was studied, showing that the formation of α'' martensite fiber is related to variant selection, beta lattice parameter increases while alpha '' accommodates deformation through adjusting lattice parameters.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Ceramics
Miguel Angel Cobos, Patricia de la Presa, Ines Puente-Orench, Irene Llorente, Irene Morales, Asuncion Garcia-Escorial, Antonio Hernando, Jose Antonio Jimenez
Summary: Samples with different inversion parameter values were prepared through mechanical grinding and thermal annealing treatments, and characterized by X-ray, neutron diffraction, and magnetic measurements. The coexistence of short range antiferromagnetic and ferrimagnetic ordering at low temperature was confirmed for the first time, and a different magnetic phase diagram from previous reports was obtained.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
Biswas Rijal, Sujeily Soto, Kausturi Parui, Anil Sachdev, Megan M. Butala, Michele Manuel, Richard G. Hennig
Summary: The crystal structure of the intermetallic tau(11) Al4Fe1.7Si phase, which is of interest for high-temperature structural applications, has been determined using powder neutron diffraction and density functional theory calculations. The structure exhibits a hexagonal crystal structure with site disorder and partial occupancies, and shows entropic stabilization at high temperature.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Multidisciplinary Sciences
Zhengqian Fu, Xuefeng Chen, Henchang Nie, Yanyu Liu, Jiawang Hong, Tengfei Hu, Ziyi Yu, Zhenqin Li, Linlin Zhang, Heliang Yao, Yuanhua Xia, Zhipeng Gao, Zheyi An, Nan Zhang, Fei Cao, Henghui Cai, Chaobin Zeng, Genshui Wang, Xianlin Dong, Fangfang Xu
Summary: The structure of the intermediate phase involved in the classic Pb(Zr1-xTix)O-3 is revealed to have important scientific and technological implications, which can be directly observed through in-situ imaging and diffraction methods.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Matthew S. Chambers, Dean S. Keeble, Dean Fletcher, Joseph A. Hriljac, Zoe Schnepp
Summary: The sol-gel synthesis of iron carbide nanoparticles involves the formation of multiple intermediate crystalline phases, with challenges in controlling particle size. Understanding the evolution of the system during synthesis is crucial for the wide range of applications of Fe3C nanoparticles. The importance of intermediate phases in controlling particle size has been demonstrated in this study, which is the first example of in situ total scattering analysis of a sol-gel system.
INORGANIC CHEMISTRY
(2021)
Article
Materials Science, Multidisciplinary
Pralay Paul, A. K. Rajarajan, S. Kuila, P. N. Vishwakarma, B. P. Mandal, T. V. Chandrasekhar Rao
Summary: The structural, magnetic and magneto-electric properties of polycrystalline BiFeO3 and Bi0.9-xGdxLa0.1FeO3 samples were investigated. Bi0.85Gd0.05La0.1FeO3 exhibited magnetic anisotropy, ferroelectric hysteresis behaviour, weak ferromagnetism, and non-linear dependence of magnetic and electric vectors in ME measurements.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Christian Pflug, Daniel Rudolph, Thomas Schleid, Holger Kohlmann
Summary: The crystal structures and formation reactions of lanthanum hydride selenides were studied using neutron diffraction. It was found that under certain temperature and pressure conditions, La2D2-xSe can be deuterated to La2D4Se using deuterium gas, and La2D3Se remains present even with increased pressure and temperature. The suggested structural models were confirmed through Rietveld refinement.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Jieun Kim, Derek J. Meyers, Abinash Kumar, Abel Fernandez, Gabriel A. P. Velarde, Zishen Tian, Jong-Woo Kim, James M. LeBeau, Philip J. Ryan, Lane W. Martin
Summary: The dynamics of polarization evolution and rotation in 0.68PbMg(1/3)Nb(2/3)O(3)-0.32PbTiO(3) relaxor ferroelectric thin films have been studied via in operando synchrotron-based X-ray diffraction. A frequency-limited suppression of polarization rotation was observed above ultrasonic frequencies (>= 20 kHz). The suppression at ultrasonic frequencies is attributed to the large activation field needed to move domain walls when the polarization rotates between different monoclinic phases.
Article
Chemistry, Physical
Yaoyao Han, Wenfei Liang, Xuyang Lin, Yulu Li, Fengke Sun, Fan Zhang, Peter C. Sercel, Kaifeng Wu
Summary: The study reports strong bright-exciton fine-structure splitting in solution-processed CsPbI3 perovskite quantum dots, which is robust to quantum dot size and shape heterogeneity and increases with decreasing temperature. The splitting is found to be associated with orthorhombic distortion of the perovskite lattice.
Article
Chemistry, Applied
Junhyuck Im, Jaewoo Jung, Kiho Yang, Donghoon Seoung, Yongmoon Lee
Summary: This study investigated the structural changes in zeolites fully exchanged with Sr, Cd, and Pb at temperatures ranging from room temperature to 350 degrees Celsius. The results showed that zeolites are easily dehydrated at high temperatures, and Sr and Pb may not have thermal stability while Cd remains intact.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Physical
Damian Paliwoda, Marco Fabbiani, Frederico Alabarse, Patrick Hermet, Jerome Rouquette, Francesco Di Renzo, Julien Haines
Summary: The behavior of siliceous zeolite MTW with a one-dimensional pore system under high pressure was studied, and the effects of nonpenetrating medium and penetrating argon medium on its properties were observed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Applied
Marco Fabbiani, Amine Morsli, Giorgia Confalonieri, Thomas Cacciaguerra, Francois Fajula, Julien Haines, Abdelkader Bengueddach, Rossella Arletti, Francesco Di Renzo
Summary: Chemical condensation of silicate layers has been suggested as an alternative to thermal condensation, but with limited success. The formation of MCM-22 zeolite from a mild hydrothermal precursor is a significant example of 2D-3D aluminosilicate condensation. Silanols from opposing layers are condensed through acid-driven dehydration, confirmed by XRD and NMR spectroscopy, indicating interlayer template extraction and dealumination. Gentler acid treatments promote template extraction and interlayer distance shrinkage, but lack significant silanol condensation. Template extraction is further enhanced by organic degradation in the presence of a Cu2+ catalyst.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Sebastiano Romi, Samuele Fanetti, Frederico Alabarse, Antonio M. Mio, Julien Haines, Roberto Bini
Summary: Saturated carbon nanothreads have been successfully synthesized, and their mechanical properties and reactivity have been characterized. The synthesis of double nanothreads with tunable optical properties and band gap has been demonstrated. The study also provides insights into the threshold conditions, kinetics, and structure-reaction relationship.
Article
Materials Science, Multidisciplinary
Daniel Bremecker, Andreas Wohninsland, Siegfried Teuber, K. Lalitha, Manuel Hinterstein, Juergen Roedel
Summary: NBT-based ceramics offer a stable mechanical quality factor with increasing vibration velocity compared to lead-based piezoceramics, thanks to their minor and stable extrinsic contributions. The high poling degree is identified as the cause for the small extrinsic contributions. The research provides a comprehensive assessment of NBT-based piezoceramics and compares them to PZT-based materials, revealing a decrease in extrinsic contributions in NBT-based materials.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Manuel Hinterstein, Lucas Lemos da Silva, Gaurav Vajpayee, Kai-Yang Lee, Andrew Studer
Summary: By using in situ stroboscopic neutron diffraction combined with a comprehensive structural refinement method, this study investigates the frequency-dependent structural change in the commercial actuator material PIC 151 at realistic operating frequencies. The results highlight the crucial role of the field-induced phase transformation in the kinetics of ferroelectric materials, and demonstrate the different effects of the tetragonal majority phase and the rhombohedral minority phase on the frequency dependence of strain mechanisms. Furthermore, the study provides an explanation for creep effects beyond the probed frequencies.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Frida Hemstad Danmo, Inger-Emma Nylund, Aamund Westermoen, Kenneth P. Marshall, Dragos Stoian, Tor Grande, Julia Glaum, Sverre M. Selbach
Summary: Hexagonal manganites, RMnO3, show potential for air separation with their reversible oxygen storage and release properties. However, the slow kinetics of oxygen exchange at low temperatures limits their efficiency. This study demonstrates that the oxidation kinetics of RMnO3 can be improved through Ti4+ doping and increasing the rare earth cation size, resulting in enhanced oxygen absorption rates.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Huajie Luo, Shiyu Tang, Zheng Sun, Yueyun Zhang, Yonghao Yao, Huashan Zheng, Jikun Yang, Yang Ren, Mingxue Tang, Houbing Huang, Hui Liu, Manuel Hinterstein, Jun Chen
Summary: In order to improve the thermal stability of Bi0.5Na0.5TiO3-based piezoelectrics, the researchers introduced Ag into BNT-6BT, forming BNT-6BT/100xAg composite ceramics. Experimental results show that when x=0.06, the depolarization temperature (Td) of the composite ceramics is improved to 145 degrees Celsius without compromising the piezoelectric response. This improvement is attributed to the synergistic effect of residual thermal stress, colossal grain size (above 200 μm), and oxygen vacancies. The study provides an effective method to enhance the thermal stability of BNT-based ceramics and can be applied to other systems as well.
Article
Chemistry, Physical
Frida Hemstad Danmo, Benjamin A. D. Williamson, Didrik R. Smabraten, Nikolai H. Gaukas, Elise R. ostli, Tor Grande, Julia Glaum, Sverre M. Selbach
Summary: Hexagonal manganites, RMnO3 (R = Sc, Y, Ho-Lu), exhibit reversible oxygen storage and release at temperatures of 150-400°C. The properties of oxygen storage can be controlled by varying R (3+) cations, aliovalent dopants, and crystallite sizes in the nanometer range. This study investigated nanocrystalline RMn1-x Ti (x) O-3 (R = Y, Ho, Dy; x = 0, 0.15) for oxygen absorption using thermogravimetric analysis (TGA) and high-temperature X-ray diffraction (HT-XRD) in O(2) and N-2 atmospheres. The results showed that the oxygen storage capacity increased with Ti4+ dopants and smaller crystallite sizes, along with improved thermal stability and absorption kinetics.
CHEMISTRY OF MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Ling Fan, Martin Reder, Daniel Schneider, Manuel Hinterstein, Britta Nestler
Summary: A novel phase-field model is proposed to investigate the domain structure in ferroelectric materials. The model calculates domain structures by minimizing the energy functional, taking into account the contributions from interfacial energy and phase-dependent bulk energy. Simulations are conducted to validate the effectiveness of this approach.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Materials Science, Ceramics
Marcus Bentzen, Juliana Maier, Udo Eckstein, Jianying He, Anja Henss, Neamul Khansur, Julia Glaum
Summary: Piezoelectric ceramics are being considered as stimulating materials for load-bearing applications in living organisms. Developing ceramic films on medically accredited metals is a promising approach to compensate for their brittle nature. Aerosol deposition allows for the production of highly dense thick films at room temperature, however, a thermal annealing step is needed to enhance their functional properties.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Hao Yang, Jinyan Zhao, Jian Zhuang, Manuel Hinterstein, Wei Ren, Zuo-Guang Ye, Nan Zhang
Summary: In this study, a polycrystalline ceramic material was investigated to understand the origin of its electromechanical strain. An ergodic-relaxor to nonergodic-relaxor transition was observed under a weak electric field, and a more stable long-range ferroelectric phase was induced under a larger electric field. The reversible phase transition was accompanied by the process of local polarization freezing and ferroelectric domain growth, which contributed to the macroscopic strain.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Manuel Hinterstein, Lucas Lemos da Silva, Michael Knapp, Alexander Schoekel, Martin Etter, Andrew Studer
Summary: Complex functional materials are important in energy-related applications and materials science. Understanding their structural mechanisms is challenging due to correlated coexisting phases and microstructures. This study demonstrates that neutron diffraction can be used to investigate such complex materials, revealing details of phase transformation under applied electric fields in barium titanate, and uncovering the strain and stress mechanisms involved.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2023)
Article
Materials Science, Multidisciplinary
Gobinda Das Adhikary, Gudeta Jafo Muleta, Getaw Abebe Tina, Deepak Sharma, Bhoopesh Mahale, Lucas Lemos da Silva, Manuel Hinterstein, Anatoliy Senyshyn, Rajeev Ranjan
Summary: This study investigates the KNN-modified NBT-based lead-free piezoelectric materials and finds that increasing KNN concentration weakens the direct piezoelectric response, while achieving the maximum electrostrain in the mixed state. It is revealed that KNN improves the weak signal piezoresponse at low concentration, and induces in-phase octahedral tilt and weakens the long-range ferroelectric order at high concentration. The mixed state exhibits a field-driven ferroelectric-to-relaxor transformation and the enhanced electrostrain is associated with increased correlation lengths of the short-ranged tetragonal and rhombohedral ferroelectric regions.
Article
Materials Science, Multidisciplinary
G. Hearne, V. Ranieri, P. Hermet, J. Haines, O. Cambon, J. L. Bantignies, P. Fertey, T. Stuerzer, M. Poienar, J. Rouquette
Summary: This study investigates the hydrogen bonds in mixed-valence barbosalite. Infrared spectroscopy shows softening and broadening of the O-H stretch modes below 10 GPa. Single-crystal x-ray diffraction confirms the pseudosymmetrization of the original unit cell and changes in the O-H vibrational mode. These indicate the delocalization of protons and strengthening of hydrogen bonds under pressure. Fe Mossbauer spectroscopy further reveals valence fluctuations of Fe2+ and Fe3+ at proximate cations of the hydrogen bonds in the range of 10-30 GPa. This research exemplifies the interplay between proton and electron dynamics in the same condensed phase.
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.
