Ferroelectric phase-transition-assisted anomaly in the electric resistivity (FPTAA) of lead-free PTC thermistors

Zajc, I.; Drofenik, Miha

doi:10.1007/s10854-017-8216-4

Cited by 2 publications

(3 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The anomaly in the resistivity for this novel class of PTC thermistor will occur at temperatures close to the T C and might also occur at temperatures of the ferroelectric phases with a T C higher than that of BT, as shown in our previous contribution [8]. Here, the explanation of the PTCR effect of the thermistor at the Curie temperature of the BT constitutive phase is based on the abrupt crystallite shape change at T C , where the c-axis shrinks to a relatively large degree.…”

Section: Resultssupporting

confidence: 65%

“…Such courses of R(T) are not known among ceramic PTC thermistors. The mechanism of the PTCR anomaly can be treated of the ''ferroelectric phase transition-assisted anomaly in the electrical resistivity'' (FPTAA) [8]. Here, the BT ferroelectric constitutive phase, which exhibits the transition between the tetragonal and cubic BaTiO 3 at the Curie temperature, induces a noticeable shrinkage of the composite at the T C , Fig.…”

Section: Resultsmentioning

confidence: 99%

“…This isolating phase is crucial and must exhibit, at a distinct temperature, an irregularity, i.e., a significant change in the temperature coefficient of expansion [5], a crystal transformation, and/or change in its crystal morphology [6]. Recently, a new type of PTCR composite based on the phenomenon known as the ''ferroelectric phase-transition-assisted anomaly in the electrical resistivity'' (FPTAA) was reported [7,8]. Here, the BaTiO 3 @Ni composite was considered in the context of the recently reported FPTAA phenomenon.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The jump-like PTCR effect in a Ni-BaTiO3 magnetic composite

Zajc

Drofenik

2022

J Mater Sci: Mater Electron

Self Cite

View full text Add to dashboard Cite

The ceramic composites BaTiO3@Ni, composed of a conducting nickel and a highly resistive ferroelectric BaTiO3 phase, exhibiting a positive temperature coefficient of electrical resistivity (PTCR), are prepared using a conventional ceramic method at less than 1000 °C. The BaTiO3@Ni composites show a jump-like PTCR effect in electrical resistivity by about eight orders of magnitude (ρmax/ρmin ≈ 108) with ρmin < 1 Ωcm. This is the first example of a standard PTCR element with a relatively high magnetization. The grain relocations (a microstructural rearrangement) on a microscopic scale in the composite are filmed using a transmission electron microscope while heating through the ferroelectric phase transition (Curie temperature), which induces the PTCR anomaly. The resistivity anomaly of the composite is explained in terms of the ferroelectric phase transition-assisted anomaly in the electrical resistivity.

show abstract

Section: Resultssupporting

confidence: 65%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The jump-like PTCR effect in a Ni-BaTiO3 magnetic composite

Zajc

Drofenik

2022

J Mater Sci: Mater Electron

Self Cite

View full text Add to dashboard Cite

show abstract

Gdを添加したBaTiO3-(Bi1/2K1/2)TiO3系無鉛高温用PTCR材料の作製

TAKEUCHI

Noguchi

2023

J. Soc. Mat. Sci., Japan

View full text Add to dashboard Cite

Fabrication of high Curie point (Tc) PTCR materials using BaTiO3 (BT)-(Bi1/2K1/2)TiO3 (BKT) ceramics was investigated. Fine powders of BT, which was synthesized by hydrothermal process, were used as starting materials. BT powders, Bi2O3, KHCO3, TiO2 and Gd(NO3)3 (water solution) were mixed with (C2H5O)4Si by wet milling for 24 h. After drying, the powders were pressed into disks, which were diameter of 20 mm and thickness of 2 mm. These disks were sintered at 1130 -1280 °C for 2 h in air. The samples containing 5 -7 mol% BKT have the room temperature resistivity lower than 600 Ωcm, PTCR jump higher than 2.4 order of magnitude, and Tc higher than 175 °C. Especially, the sample containing 6 mol% BKT has the room temperature resistivity of 270 Ωcm, PTCR jump of 2.4 order of magnitude, and Tc of 185 °C and it was the excellent high Tc lead-free PTCR materials which was fabricated by firing in air.

show abstract

Ferroelectric phase-transition-assisted anomaly in the electric resistivity (FPTAA) of lead-free PTC thermistors

Cited by 2 publications

References 8 publications

The jump-like PTCR effect in a Ni-BaTiO3 magnetic composite

The jump-like PTCR effect in a Ni-BaTiO3 magnetic composite

Gdを添加したBaTiO<sub>3</sub>-(Bi<sub>1/2</sub>K<sub>1/2</sub>)TiO<sub>3</sub>系無鉛高温用PTCR材料の作製

Contact Info

Product

Resources

About