Large electrocaloric efficiency over a broad temperature span in lead-free BaTiO3-based ceramics near room temperature

2017 ◽  
Vol 111 (20) ◽  
pp. 202902 ◽  
Author(s):  
Tangyuan Li ◽  
Xinyu Liu ◽  
Sheng Shi ◽  
Yihao Yin ◽  
Hongfa Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Lead Free

Electrocaloric properties of lead-free ferroelectric ceramic near room temperature

2021 ◽  
Vol 127 (6) ◽  
Author(s):  
Hend Kacem ◽  
Ah. Dhahri ◽  
Mohamed Amara Gdaiem ◽  
Z. Sassi ◽  
L. Seveyrat ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ferroelectric Ceramic ◽  
Lead Free

Enhanced electrocaloric strengths at room temperature in (SrxBa1−x)(Sn0.05Ti0.95)O3 lead-free ceramics

2021 ◽  
Vol 871 ◽  
pp. 159519
Author(s):  
Sheng-Guo Lu ◽  
Xiongwei Lin ◽  
Jiang Li ◽  
Dandan Li ◽  
Yingbang Yao ◽  
...  
Keyword(s):  
Room Temperature ◽  
Lead Free ◽  
Lead Free Ceramics

The Characteristic of the La3Ga5SiO14 Single Crystal Grown by Vertical Bridgman Method in Ar Atmosphere

2006 ◽  
Vol 510-511 ◽  
pp. 842-845 ◽  
Author(s):  
Noriko Bamba ◽  
Kentaro Kato ◽  
Toshinori Taishi ◽  
Takayuki Hayashi ◽  
Keigo Hoshikawa ◽  
...  
Keyword(s):  
Melting Point ◽  
Single Crystal ◽  
Single Crystals ◽  
Room Temperature ◽  
Color Change ◽  
Piezoelectric Materials ◽  
Lead Free ◽  
Piezoelectric Constant ◽  
Interstitial Oxygen ◽  
Vertical Bridgman

Langasite (La3Ga5SiO14: denoted by LGS) single crystal is one of the lead free piezoelectric materials with high piezoelectricity that is maintained up to its melting point (1470°C). Although LGS single crystals have usually been grown by Czochralski (CZ) method in oxygen contained atmosphere to prevent evaporation of Ga, they were grown by the vertical Bridgman (VB) method in Ar atmosphere without oxygen, and their properties were evaluated in this work. Transparent and colorless LGS single crystals were successfully obtained without Ga evaporation by the VB method in Ar atmosphere, and their resistivity at room temperature was much higher than that grown by conventional CZ method. Piezoelectric constant d11 of the crystal grown by the VB method was 6 x 10-12 C/N, which was close to that of the crystal grown by CZ method. The colorless transparent LGS single crystal turned to orange and its resistivity decreased by annealing in air. Since an orange-colored transparent LGS single crystal has been grown by conventional CZ method, this indicates that color change and the resistivity decrease of LGS crystal is caused by extra interstitial oxygen atoms in the crystal.

Effect of Sintering Temperature on Structure and Dielectric Properties of Lead Free K0.5Na0.5NbO3 Prepared via Hot Isostatic Pressing

2017 ◽  
Vol 888 ◽  
pp. 42-46 ◽  
Author(s):  
Fatin Khairah Bahanurdin ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Hot Isostatic Pressing ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Tangent Loss ◽  
Isostatic Pressing ◽  
Tan Δ

In this research, alkaline niobate known as K0.5Na0.5NbO3 (KNN) lead-free piezoelectric ceramic was synthesis by solid state reaction method which pressing at different sintering temperatures (1000 °C and 1080 °C) prepared via hot isostatic pressing (HIP)). The effect of sintering temperature on structure and dielectric properties was studied. The optimum sintering temperature (at 1080 °C for 30 minutes) using hot isostatic pressing (HIP) was successfully increase the density, enlarge the particle grain size in the range of 0.3 µm – 2.5 µm and improves the dielectric properties of K0.5Na0.5NbO3 ceramics. The larger grain size and higher density ceramics body will contribute the good dielectric properties. At room temperature, the excellent relative permittivity and tangent loss recorded at 1 MHz (ɛr = 5517.35 and tan δ = 0.954), respectively for KNN1080HIP sample. The KNN1080HIP sample is also exhibits highest relative density which is 4.485 g/cm3. The ɛr depends upon density and in this work, the density increase as the sintering temperature increase, which resulting the corresponding ɛr value also increases.

Enhanced electrocaloric effect in lead-free organic and inorganic relaxor ferroelectric composites near room temperature

2018 ◽  
Vol 112 (19) ◽  
pp. 193902 ◽  
Author(s):  
Haibibu Aziguli ◽  
Xin Chen ◽  
Yang Liu ◽  
Guang Yang ◽  
Ping Yu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Relaxor Ferroelectric ◽  
Lead Free ◽  
Electrocaloric Effect

Lead-free hybrid ferroelectric material based on formamidine: [NH2CHNH2]3Bi2I9

2019 ◽  
Vol 7 (10) ◽  
pp. 3003-3014 ◽  
Author(s):  
Przemysław Szklarz ◽  
Anna Gągor ◽  
Ryszard Jakubas ◽  
Piotr Zieliński ◽  
Anna Piecha-Bisiorek ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Room Temperature ◽  
Ferroelectric Material ◽  
Lead Free ◽  
Ferroelectric Crystals ◽  
Complex Sequences

Novel room-temperature ferroelectric crystals with complex sequences of phase transitions.

The Effects of Electromigration to the Solder Joint Formation: A Comparison Between 99.3Sn-0.7Cu and 96.5Sn-3.0Ag-0.5Cu Lead Free Solder

2012 ◽  
Vol 622-623 ◽  
pp. 195-199 ◽  
Author(s):  
M.A.A. Mohd Salleh ◽  
A.R. Nik Nurhidayatul Suhada ◽  
Flora Somidin ◽  
Rafezi Ahmad Khairel ◽  
C.S. Lee ◽  
...  
Keyword(s):  
Solder Joint ◽  
Room Temperature ◽  
Solder Joints ◽  
Research Work ◽  
Cathode Region ◽  
Lead Free ◽  
Lead Free Solder ◽  
Joint Formation ◽  
Current Stress ◽  
Free Solder

Electromigration effects on the solder joint formation of 99.3Sn-0.7Cu and 96.5Sn-3.0Ag-0.5Cu lead-free solder with Cu electroplated Ni layer wire were investigated. The electromigration effects on the solder joints were studied after current density stressing at 1 x 103 A/cm2 in room temperature for 0 h, 120 h, and 240 h. The research work found that intermetallic compound (IMC) formation on the joint is increases for both solders with longer period of current stress applied. Higher IMC thickness growth in 99.3Sn-0.7Cu solder joint compared to 99.3Sn-0.7Cu is detected and both anode regions of the solder joints show higher IMC thickness growth compared to cathode region. Experimental results show 99.3Sn-0.7Cu solder joint is more prone to failure under current stress compared to 96.5Sn-3.0Ag-0.5Cu solder joint with thicker IMC which translates to higher brittleness.

Origin of Room Temperature Ferromagnetism in Cr-Doped Lead-Free Ferroelectric Bi0.5Na0.5TiO3 Materials

2017 ◽  
Vol 46 (6) ◽  
pp. 3367-3372 ◽  
Author(s):  
L. T. H. Thanh ◽  
N. B. Doan ◽  
N. Q. Dung ◽  
L. V. Cuong ◽  
L. H. Bac ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Lead Free
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