Article
Materials Science, Ceramics
Vivek Korde, Naresh Patil, Sanjay Shamkuwar
Summary: Ferroelectric domain engineering is important for studying the dipolar structure of these materials, which is formed due to defects and imperfections introduced through doping. In this study, an Al-doped KNbO3 single crystal was prepared and the domain structure was studied by applying electric fields. The critical field for nucleation of new domains in the Al-doped KNbO3 crystal was found to be slightly lower than that of the pure KNbO3 crystal.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Rui Tang, Hetuo Chen, Guohong Zhou, Jianhua Nie, Xianpeng Qin, Zhenhai Xue
Summary: The phase composition, microstructure, electrical and thermal properties of hot-pressed AlN-2 wt% Yb2O3-4 wt% Sm2O3-x wt% TiN (x = 0, 0.4, 0.8, 1, 2, 3, 4) ceramics were investigated. The addition of Yb2O3 and Sm2O3 resulted in densely sintered samples due to the formation of secondary phases. At temperatures higher than 1700 degrees C, the resistivity of AlN ceramics with 2 wt% Yb2O3-4 wt % Sm2O3 significantly decreased. Addition of TiN from 0.4-4.0 wt% reduced the resistivity while maintaining thermal conductivity and high compactness at 1650 degrees C.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Dan Wang, Xiaodan Wang, Hai Ma, Xiaodong Gao, Jiafan Chen, Shunan Zheng, Hongmin Mao, Huajun Chen, Xionghui Zeng, Ke Xu
Summary: A series of Dy3+ and Eu3+ implanted AlN films grown by HVPE method were prepared and their crystal structure, cathodoluminescence spectra, energy transfer mechanism and chromaticity properties were investigated. Results showed that the luminescence color of the films can be effectively controlled by changing the fluence of Eu3+.
Article
Nanoscience & Nanotechnology
Yiwen Song, Carlos Perez, Giovanni Esteves, James Spencer Lundh, Christopher B. Saltonstall, Thomas E. Beechem, Jung In Yang, Kevin Ferri, Joseph E. Brown, Zichen Tang, Jon-Paul Maria, David W. Snyder, Roy H. Olsson, Benjamin A. Griffin, Susan E. Trolier-McKinstry, Brian M. Foley, Sukwon Choi
Summary: RF MEMS based on Al1-xScxN are being favored over AlN-based devices for their higher achievable bandwidths suitable for 5G networks. However, overheating of Al1-xScxN FBARs limits power handling, and reducing abnormally oriented grain density improves thermal performance of the devices.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Christopher Schutzeichel, Nataliya Kiriy, Anton Kiriy, Brigitte Voit
Summary: This paper presents a novel microstructuring method that allows patterning of n-doped silicon substrates without the need for etch-masks or stencils. The method involves simple alkaline etching under illumination, controlled by p-doped micro-sized implants buried beneath the n-doped layer. The buried implants act as micro-sized photovoltaic cells, generating a flux of electrons to protect the silicon oxide layer from etching, ultimately leading to substrate microstructuring.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Review
Engineering, Electrical & Electronic
Rui M. R. Pinto, Ved Gund, Carlos Calaza, K. K. Nagaraja, K. B. Vinayakumar
Summary: This review introduces the wet and dry etching methods for aluminum nitride (AlN) thin-films, and discusses the effects of etching parameters on the overall surface characteristics.
MICROELECTRONIC ENGINEERING
(2022)
Article
Chemistry, Physical
Zhanglin Chen, Wei Cui, Kaiming Zhu, Chunguang Zhang, Chuandong Zuo, Yude Niu, Qi Wang, Xuanyi Yuan, Guanghua Liu
Summary: An orange-red emitting Mn2+/Si4+ co-doped AlN phosphor was prepared by combustion synthesis method, and its luminescence properties, afterglow performance, and structure were systematically studied. The co-doping of Si4+ was found to enhance the luminescence intensity and afterglow time, with possible mechanisms discussed using XPS analysis. A shallower trap level was formed after Si4+ co-doping, leading to improved afterglow performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Applied
Yu-Chen Chang, Ying-Chung Chen, Ruei-Ting Huang, Yu-Ting Chen, Su-Ciang Chen, Chien-Chuan Cheng, Cheng-Fu Yang
Summary: This paper investigates the fabrication process of solidly mounted resonator (SMR) devices using aluminum nitride (AlN) and gallium-doped aluminum nitride (AlGaN) films. The crystalline structure and surface properties of the films were characterized by XRD, EDS, and SEM analyses. The frequency response of the fabricated SMR devices was measured using a network analyzer.
MODERN PHYSICS LETTERS B
(2022)
Article
Engineering, Electrical & Electronic
Y. Chen, Y. Xing, J. T. Gong, Qi Li, X. Guo
Summary: This paper investigates the wet etching rate distribution of GaN < 0001 > crystal zone in H3PO4 etchant with different temperatures and concentrations using wagon-wheel structures fabricated on GaN (0 0 0 1) substrate. The results show that GaN exhibits six-fold symmetrical anisotropy about the c-axis in the < 0001 > crystallographic zone, and H3PO4 etching results in lower surface roughness and etch rate fluctuation compared to AZ400K etching. The apparent activation energy and the dependence of etch rate on concentration are also analyzed in this study. The step flow theory is successfully applied to explain the etching rate anisotropy at the atomic scale.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Physics, Multidisciplinary
Wenhui Wan, Na Kang, Yanfeng Ge, Yong Liu
Summary: In this study, the structural and magnetic properties of Si-doped bulk and 2D AlN were systematically investigated. It was found that Si atoms prefer to substitute Al atoms in both bulk and 2D AlN, and their behavior differs under different conditions. The results also suggest that 2D AlN doped with group IV elements has potential applications in spintronic devices.
FRONTIERS IN PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Peng-Lin Wang, Hui-Qing Sun, Xiao Ding, Zhi-Hui Huang, Yuan Li, Fan Xia, Xiao-Yu Xia, Miao Zhang, Jian-Cheng Ma, Xiu-Yang Tan, Liang Xu, Zhi-You Guo
Summary: The RF performance of novel Sc-Doped GaN HEMTs with asymmetric air-bridge structure was analyzed using TCAD software. By utilizing an innovative design with an asymmetrical air bridge and ScAlN layer, significant improvements in transconductance and electron velocity, as well as a reduction in electron concentration, were achieved in the device. Additionally, the combined influence of the air bridge and scandium layer structure on capacitance and other parameters provides a useful approach for enhancing the DC and RF characteristics of GaN HEMTs.
RESULTS IN PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Apratim Khandelwal, Zhongjie Ren, Shunya Namiki, Zhendong Yang, Nitin Choudhary, Chao Li, Ping Wang, Zetian Mi, Xiuling Li
Summary: This study uses magnetron sputtering to adjust the intrinsic stress in aluminum nitride (AlN) thin films and achieves the spontaneous formation of compressive and tensile bilayer membranes through a 3D MEMS approach. By combining AlN with other materials, AlN-based hybrid microtubes with a diameter of 6 micrometers are successfully fabricated. Compared with other stressed thin films, AlN-based microtubes show better structural controllability and versatility.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Apratim Khandelwal, Zhongjie Ren, Shunya Namiki, Zhendong Yang, Nitin Choudhary, Chao Li, Ping Wang, Zetian Mi, Xiuling Li
Summary: Aluminum nitride (AlN) thin films with tailored intrinsic stress were fabricated using magnetron sputtering, and 3D MEMS structures were realized by combining ultrathin AlN bilayer membranes. High-performance microtubes were demonstrated by combining AlN with other materials, and tubular Al1-xScxN piezoelectric devices were successfully fabricated for the first time.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Inorganic & Nuclear
Jean Yves Uwamungu, Anjan Kumar, Safa K. Hachim, Zainab S. Abbas, Alaa Dhari Jawad Al-bayati, Asala Salam Jaber, Farzad Molani, Mustafa M. Kadhim
Summary: Developing a sensor for detecting SF6 decomposed gasses is crucial for electrical equipment insulation. This study uses first-principles density functional theory computations to investigate the potential use of metal-doped one-dimensional nanomaterials in gas sensors and their sensitivity, adsorption, and electronic properties. Pt-doped aluminum nitride nanotube (Pt-AlNNT) is found to have suitable sensing and adhesion properties for detecting SF6 decomposed gasses. These findings provide useful insights into the development of Pt-AlNNT as a sensor in electrical equipment insulation.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Physics, Applied
O. Gronenberg, R. Marquardt, R. Lamprecht, Y. Ekici, U. Schuermann, H. Kohlstedt, L. Kienle
Summary: This study investigates the ferroelectric properties of sputtered and undoped HfO2 and reveals the effects of different temperature treatments on its performance. The research finds that temperature treatments affect the interfaces of the TiN electrodes and the microstructure and defect concentration of HfO2, leading to variations in device performance.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Acoustics
Smitha Shetty, Prapassorn Numkiatsakul, Kevin Wickline, Regina Incarnato, Haifeng Wang, Hal Kunkel, Clive A. Randall, Susan Trolier-McKinstry
Summary: A family of three phase polymer-ceramic-metal electrically conducting composites were developed using cold sintering for acoustic matching in medical ultrasound transducers. The composites exhibited a range of acoustic impedance, high density, and low attenuation. Additionally, non-conducting low impedance materials were achieved and the scaling of the composites was demonstrated.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2022)
Article
Physics, Applied
Yongtao Liu, Shelby S. Fields, Takanori Mimura, Kyle P. Kelley, Susan Trolier-McKinstry, Jon F. Ihlefeld, Sergei V. Kalinin
Summary: This study explores the electronic conduction pathways in dielectric thin films using automated experiments in scanning probe microscopy. By employing large field of view scanning and higher spatial resolution, variable behaviors of conductive spots, including disappearance, reappearance, and new development, are observed during continuous scanning. The automated workflow can be integrated into various microscopy techniques.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Tianning Liu, Pannawit Tipsawat, Wanlin Zhu, Thomas N. Jackson, Mani Sivaramakrishnan, Peter Mardilovich, Thorsten Schmitz-Kempen, Susan Trolier-McKinstry
Summary: When using double-beam laser interferometry to measure the piezoelectric coefficient of a film on a substrate, it is important to consider the limitations when the film experiences excessive bending deformation. This work demonstrates the challenges faced when measuring fully released PZT films and highlights the errors that can occur.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Analytical
Christopher Cheng, Travis Peters, Ajay Dangi, Sumit Agrawal, Haoyang Chen, Sri-Rajasekhar Kothapalli, Susan Trolier-McKinstry
Summary: This study investigates the improvement of receive sensitivity in PZT piezoelectric micromachined ultrasound transducers (PMUTs) by applying a DC bias. The results show that the PMUT receive sensitivity and photoacoustic signal can be significantly improved by applying a DC bias.
Article
Physics, Applied
Christopher Cheng, Travis Peters, Susan Trolier-McKinstry
Summary: The crack initiation stresses of different lead zirconate titanate (PZT) film compositions were investigated. The film thickness served as the limiting flaw size for failure of the film/substrate stack in a specific composition, while the characteristic stack strength and Weibull modulus varied in different compositions.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Charalampos Fragkiadakis, Subramanian Sivaramakrishnan, Thorsten Schmitz-Kempen, Peter Mardilovich, Susan Trolier-McKinstry
Summary: This paper systematically investigates the self-heating mechanism in piezoMEMS transducer arrays and quantifies the relationship between self-heating and waveform parameters. Thermal modeling based on hysteresis loss measurement is found to be in excellent agreement with experimental data. The self-heating model can be used to improve thermal design and functional heating in piezoMEMS.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Gavin Hennessey, Travis Peters, Pannawit Tipsawat, Marti Checa, Liam Collins, Susan Trolier-McKinstry
Summary: This paper investigates the effect of microstructural features on domain wall motion pinning in PZT films on polycrystalline substrates. The study reveals that the behavior varies with the misorientation angle and proximity to grain boundaries. Random grain boundaries exhibit deeper minima and larger widths of influence compared to coincident site lattice boundaries. Triple points with more random boundaries exhibit non-Rayleigh behavior, suggesting deep potential minima or regions unfavorable for domain wall motion.
Article
Physics, Applied
Travis Peters, Wanlin Zhu, Marti Checa, Liam Collins, Susan Trolier-McKinstry
Summary: In undoped lead zirconate titanate films, domain walls move in clusters with a correlation length of 0.5-2 μm. Nb doping increases the concentration or mobility of domain walls without changing the cluster area, while Mn doping reduces the contribution of mobile domain walls without changing the cluster area. In both Nb and Mn doped films, the cluster area increases and the cluster density drops as the film thickness increases from 250 to 1250 nm, as observed from the analysis of irreversible to reversible ratios of the Rayleigh coefficients.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Wanlin Zhu, Fan He, John Hayden, Jung In Yang, Pannawit Tipsawat, Jon-Paul Maria, Susan Trolier-McKinstry
Summary: This paper presents the retention behavior of Al0.93B0.07N thin films, which belong to the novel family of wurtzite ferroelectrics. The experimental results show that bipolar cycling of the film stacks induces wake-up and a region of constant switchable polarization. The films exhibit excellent retention of the stored polarization state. The opposite state measurements show slightly inferior data retention, but even after 3.6 x 10(6) s (1000 h) at 200 degrees C, the OS signal margin still exceeds 200 mu C/cm(2). The predicted OS retention is 82% after 10 years of baking at 200 degrees C.
APPLIED PHYSICS LETTERS
(2023)
Article
Multidisciplinary Sciences
V. Sebastian Calderon, John Hayden, Steven M. Baksa, William Tzou, Susan Trolier-McKinstry, Ismaila Dabo, Jon -Paul Maria, Elizabeth C. Dickey
Summary: Ferroelectric wurtzites have the potential to revolutionize modern microelectronics. This study observed and quantified real-time polarization switching of ferroelectric wurtzite at the atomic scale. A polarization reversal model was proposed, providing an important first step for property engineering efforts.
Article
Chemistry, Physical
Betul Akkopru-Akgun, Susan Trolier-McKinstry
Summary: Lead zirconate titanate (PZT) films with high Nb concentrations (6-13 mol%) were fabricated by chemical solution deposition method. The stoichiometry of the films can be self-compensated up to 8 mol% Nb, and single phase films can be obtained with 10 mol% PbO excess in the precursor solution. However, higher Nb concentrations resulted in multi-phase films unless the excess PbO level was reduced. The dielectric and piezoelectric properties of the films were significantly degraded with increased Nb concentrations, but can be improved by reducing the PbO level to 6 mol%.
Article
Materials Science, Multidisciplinary
Yongke Yan, Liwei D. Geng, Li-Qian Cheng, Xiaotian Li, Haoyang Leng, Ke Wang, Bed Poudel, Amin Nozariasbmarz, Mohan Sanghadasa, Susan Trolier-McKinstry, Qi-Ming Zhang, Yu U. Wang, Shashank Priya
Summary: The physical properties of complex perovskite ferroelectrics depend on the degree of order/disorder and the scale of the ordered domains. In this study, the electrocaloric properties of three representative complex perovskite ferroelectrics were evaluated. The high EC performance of Pb(Sc1/2Ta1/2)O-3 (PST) was found to be related to the ordering of B-site cations (Sc3+ and Ta5+) and a long coherence length.
Article
Physics, Applied
Jon F. Ihlefeld, Travis Peters, Samantha T. Jaszewski, Takanori Mimura, Benjamin L. Aronson, Susan Trolier-McKinstry
Summary: The influence of biaxial stress on the maximum and remanent polarizations of 10 nm thick hafnium zirconium oxide thin films has been studied. It was found that reducing the intrinsic strain through the application of a compressive uniaxial stress resulted in a decrease in the remanent and maximum polarizations. The observed variation in polarization with strain is consistent with strain impacting ferroelastic switching.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Ceramics
Abdullah Jabr, Haley N. Jones, Andrea P. Arguelles, Susan Trolier-McKinstry, Clive Randall, Raul Bermejo
Summary: The cold sintering process (CSP) densifies ceramics at temperatures below 300 degrees C using a transient phase and applied pressure. Flaws compromising the mechanical strength of cold sintered materials were detected using ultrasonic evaluation, and load transfer misalignments and fast heating rates were identified as major sources of defects. By using precisely aligned punches and slow heating rates, multiple disc-shaped samples achieved homogeneous densification, high relative density (>97%), and improved strength (-120 MPa), demonstrating the feasibility of industrial implementation for CSP scaling up.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)