Tianfu Zhang
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Tianfu Zhang has a total of 23 co-authors. Here are the top co-authors by number of shared publications:
- Qiu-Xiang Liu
School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
2 shared publications - Wenhua Li
Guangdong Provincial Key Laboratory of Sensing Physics and System Integration Applications, School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, People's Republic of China
2 shared publications - Xin-Gui Tang
School of Physics and Optoelectric Engineering & Guangdong Provincial Key Laboratory of Sensing Physics and System Integration Applications Guangdong University of Technology Guangzhou China
2 shared publications - Yan-Ping Jiang
School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou Higher Education Mega Center 1 , Guangzhou 510006
2 shared publications - Ahmad Safari
Rutgers, The State University of New Jersey, USA
1 shared publication - Bi Li
School of Physics & Optoelectric Engineering, Guangdong University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China
1 shared publication
Latest Publications
- Open Access
- 28 September 2020
- Published by Springer Nature in Research Square
High Efficiency Refrigeration and Pyroelectric Energy Harvesting Applications of Lead Titanate Based Relaxer Ceramic
Relaxer ferroelectrics are highly attractive in electrocaloric due to large breakdown electric field and wide phase transition temperatures, which has great potential applications in solid-state cooling. In this work, relaxer ferroelectrics are synthesized by a traditional solid state reaction method. Phase transition and relaxer characteristics are studied by temperature dependent dielectric spectrums. Temperature dependent ferroelectric properties are also studied to calculate electrocaloric effect. Maximum value of refrigeration efficiency η ( ΔT/ΔE ) is about 0.079 K·cm/kV, our result lays a foundation and provides a reference for studying high efficiency solid-state electrocaloric refrigeration. Pyroelectric energy harvesting are studied, maximum pyroelectric energy harvesting is 279 kJ/cm 3 .
- 28 September 2020
- Published by Springer Nature in Research Square
Open AccessHigh Efficiency Refrigeration and Pyroelectric Energy Harvesting Applications of Lead Titanate Based Relaxer Ceramic
Relaxer ferroelectrics are highly attractive in electrocaloric due to large breakdown electric field and wide phase transition temperatures, which has great potential applications in solid-state cooling. In this work, relaxer ferroelectrics are synthesized by a traditional solid state reaction method. Phase transition and relaxer characteristics are studied by temperature dependent dielectric spectrums. Temperature dependent ferroelectric properties are also studied to calculate electrocaloric effect. Maximum value of refrigeration efficiency η ( ΔT/ΔE ) is about 0.079 K·cm/kV, our result lays a foundation and provides a reference for studying high efficiency solid-state electrocaloric refrigeration. Pyroelectric energy harvesting are studied, maximum pyroelectric energy harvesting is 279 kJ/cm 3 .
- 19 November 2018
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Biomedical Engineering
- Vol. 66 (6) , 1580-1587
Eco-Friendly Highly Sensitive Transducers Based on a New KNN–NTK–FM Lead-Free Piezoelectric Ceramic for High-Frequency Biomedical Ultrasonic Imaging Applications
High-frequency ultrasonic imaging with improved spatial resolution has gained increasing attention in the field of biomedical imaging. Sensitivity of transducers plays a pivotal role in determining ultrasonic image quality. Conventional ultrasonic transducers are mostly made from lead-based piezoelectric materials that may be harmful to the human body and the environment. In this study, a new (K,Na)NbO $_{3}$ -KTiNbO $_5$ -BaZrO $_{3}$ -Fe $_{2}$ O $_{3}$ -MgO (KNN-NTK-FM) lead-free piezoelectric ceramic was utilized in developing eco-friendly transducers for high-frequency biomedical ultrasonic imaging applications. A needle transducer with a small active aperture size of 0.45 × 0.55 mm $^2$ was designed and evaluated. The fabricated transducer exhibits great performance with a high center frequency (52.6 MHz), a good electromechanical coupling ( $k$ $_{eff}$ ~ 0.45), a large bandwidth (64.4% at -6 dB), and a very low two-way insertion loss (10.1 dB). Such high sensitivity is superior to those transducers based on other lead-free piezoelectric materials and can even be comparable to the lead-based ones. Imaging performance of the KNN-NTK-FM needle transducer was analyzed by imaging a wire phantom and an agar tissue-mimicking phantom. Imaging capabilities of the transducer were further demonstrated by ex vivo imaging studies on a porcine eyeball and a rabbit aorta. The results suggest that the KNN-NTK-FM piezoceramic has many attractive properties over other lead-free piezoelectric materials in developing eco-friendly highly sensitive transducers for high-frequency biomedical ultrasonic imaging applications.- 19 November 2018
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Biomedical Engineering
- Vol. 66 (6) , 1580-1587
Eco-Friendly Highly Sensitive Transducers Based on a New KNN–NTK–FM Lead-Free Piezoelectric Ceramic for High-Frequency Biomedical Ultrasonic Imaging Applications
High-frequency ultrasonic imaging with improved spatial resolution has gained increasing attention in the field of biomedical imaging. Sensitivity of transducers plays a pivotal role in determining ultrasonic image quality. Conventional ultrasonic transducers are mostly made from lead-based piezoelectric materials that may be harmful to the human body and the environment. In this study, a new (K,Na)NbO $_{3}$ -KTiNbO $_5$ -BaZrO $_{3}$ -Fe $_{2}$ O $_{3}$ -MgO (KNN-NTK-FM) lead-free piezoelectric ceramic was utilized in developing eco-friendly transducers for high-frequency biomedical ultrasonic imaging applications. A needle transducer with a small active aperture size of 0.45 × 0.55 mm $^2$ was designed and evaluated. The fabricated transducer exhibits great performance with a high center frequency (52.6 MHz), a good electromechanical coupling ( $k$ $_{eff}$ ~ 0.45), a large bandwidth (64.4% at -6 dB), and a very low two-way insertion loss (10.1 dB). Such high sensitivity is superior to those transducers based on other lead-free piezoelectric materials and can even be comparable to the lead-based ones. Imaging performance of the KNN-NTK-FM needle transducer was analyzed by imaging a wire phantom and an agar tissue-mimicking phantom. Imaging capabilities of the transducer were further demonstrated by ex vivo imaging studies on a porcine eyeball and a rabbit aorta. The results suggest that the KNN-NTK-FM piezoceramic has many attractive properties over other lead-free piezoelectric materials in developing eco-friendly highly sensitive transducers for high-frequency biomedical ultrasonic imaging applications.- Open Access
Switching Characteristics and High-Temperature Dielectric Relaxation Behaviours of Pb(Zn1/3Nb2/3)0.91Ti0.09O3 Single Crystal
This work evaluated the resistance switching characteristics in the (100)-oriented Pb(Zn1/3Nb2/3)0.91Ti0.09O3 (PZNT) single crystal. The current hysteresis can be closely related to the ferroelectric polarization and we provided a possible explanation using a model about oxygen vacancies to analyze the mechanism of switching. The obvious frequency dispersion of the relative permittivity signified the relaxer-type behavior of the sample. The value of the relaxation parameter γ = 1.48 was estimated from the linear fit of the modified Curie-Weiss law, indicating the relaxer nature. High-temperature dielectric relaxation behaviors were revealed in the temperature region of 400–650 °C. In addition, under the measuring frequency of 10 kHz, εr was tunable by changing the electric field and the largest tunability of εr reached 14.78%. At room temperature, the high pyroelectric coefficient and detectivity figure of merit were reported.
Open AccessSwitching Characteristics and High-Temperature Dielectric Relaxation Behaviours of Pb(Zn1/3Nb2/3)0.91Ti0.09O3 Single Crystal
This work evaluated the resistance switching characteristics in the (100)-oriented Pb(Zn1/3Nb2/3)0.91Ti0.09O3 (PZNT) single crystal. The current hysteresis can be closely related to the ferroelectric polarization and we provided a possible explanation using a model about oxygen vacancies to analyze the mechanism of switching. The obvious frequency dispersion of the relative permittivity signified the relaxer-type behavior of the sample. The value of the relaxation parameter γ = 1.48 was estimated from the linear fit of the modified Curie-Weiss law, indicating the relaxer nature. High-temperature dielectric relaxation behaviors were revealed in the temperature region of 400–650 °C. In addition, under the measuring frequency of 10 kHz, εr was tunable by changing the electric field and the largest tunability of εr reached 14.78%. At room temperature, the high pyroelectric coefficient and detectivity figure of merit were reported.
- Open Access
High Energy Storage Density and Impedance Response of PLZT2/95/5 Antiferroelectric Ceramics
(Pb0.97La0.02)(Zr0.95Ti0.05)O3 (PLZT2/95/5) ceramics were successfully prepared via a solid-state reaction route. The dielectric properties were investigated in the temperature region of 26–650 °C. The dielectric diffuse anomaly in the dielectric relaxation was found in the high temperature region of 600–650 °C with increasing the measuring frequency, which was related to the dynamic thermal process of ionized oxygen vacancies generated in the high temperature. Two phase transition points were detected during heating, which were found to coexist from 150 to 200 °C. Electric field induced ferroelectric to antiferroelectric phase transition behavior of the (Pb0.97La0.02)(Zr0.95Ti0.05)O3 ceramics was investigated in this work with an emphasis on energy storage properties. A recoverable energy-storage density of 0.83 J/cm3 and efficiency of 70% was obtained in (Pb0.97La0.02)(Zr0.95Ti0.05)O3 ceramics at 55 kV/cm. Based on these results, (Pb0.97La0.02)(Zr0.95Ti0.05)O3 ceramics with a large recoverable energy-storage density could be a potential candidate for the applications in high energy-storage density ceramic capacitors.
Open AccessHigh Energy Storage Density and Impedance Response of PLZT2/95/5 Antiferroelectric Ceramics
(Pb0.97La0.02)(Zr0.95Ti0.05)O3 (PLZT2/95/5) ceramics were successfully prepared via a solid-state reaction route. The dielectric properties were investigated in the temperature region of 26–650 °C. The dielectric diffuse anomaly in the dielectric relaxation was found in the high temperature region of 600–650 °C with increasing the measuring frequency, which was related to the dynamic thermal process of ionized oxygen vacancies generated in the high temperature. Two phase transition points were detected during heating, which were found to coexist from 150 to 200 °C. Electric field induced ferroelectric to antiferroelectric phase transition behavior of the (Pb0.97La0.02)(Zr0.95Ti0.05)O3 ceramics was investigated in this work with an emphasis on energy storage properties. A recoverable energy-storage density of 0.83 J/cm3 and efficiency of 70% was obtained in (Pb0.97La0.02)(Zr0.95Ti0.05)O3 ceramics at 55 kV/cm. Based on these results, (Pb0.97La0.02)(Zr0.95Ti0.05)O3 ceramics with a large recoverable energy-storage density could be a potential candidate for the applications in high energy-storage density ceramic capacitors.