Dielectric properties with high dielectric permittivity and low loss tangent and nonlinear electrical response of sol-gel synthesized Na1/2Sm1/2Cu3Ti4O12 perovskite ceramic
“…The Ti 3+ /Ti 4+ ratio was 2.37/97.63 and 2.69/97.31% for NY9h and NY15h, respectively. The presence of Cu + and Ti 3+ is in agreement with earlier literature reports 30 , 34 . Cu + and Ti 3+ in the NYCTO lattice indicates the presence of V O in the structure.…”
Section: Discussionsupporting
confidence: 93%
“…This indicates that DC conduction predominates in NYCTO ceramics 10 , 11 . Such dielectric behavior is similar to that reported in Na 1/2 Sm 1/2 Cu 3 Ti 4 O 12 ceramics 30 . In the current work, the temperature coefficients of ε′ at 1 kHz for the NY9h and NY15h ceramics were evaluated.…”
A modified sol-gel method was used to successfully produce Na1/2Y1/2Cu3Ti4O12 ceramics with high dielectric permittivity. The dielectric permittivity of Na1/2Y1/2Cu3Ti4O12 ceramics reaches values larger than 104 at room temperature and 1 kHz. Moreover, these ceramics exhibit two distinct thermally induced dielectric relaxations over a broad temperature range. The loss tangent is indeed small, ~0.032–0.035. At low temperatures, dielectric relaxation was attributed to the oxygen vacancy effect, while at high temperatures, it was attributed to grain boundary and sample-electrode contact effects. Our calculations revealed that Y and Na ions are likely to occupy Ca and Cu sites, respectively. As a result, other Cu related phases, especially CuO, were observed at the grain boundaries. Based on our analysis, there is a charge compensation between Na and Y ions in Na1/2Y1/2Cu3Ti4O12. Additionally, the Cu+ and Ti3+ states observed in our XPS study originate from the presence of an oxygen vacancy in the lattice. Last, the primary cause of the enormous dielectric permittivity of Na1/2Y1/2Cu3Ti4O12 ceramics primarily comes from the internal barrier layer capacitor effect.
“…The Ti 3+ /Ti 4+ ratio was 2.37/97.63 and 2.69/97.31% for NY9h and NY15h, respectively. The presence of Cu + and Ti 3+ is in agreement with earlier literature reports 30 , 34 . Cu + and Ti 3+ in the NYCTO lattice indicates the presence of V O in the structure.…”
Section: Discussionsupporting
confidence: 93%
“…This indicates that DC conduction predominates in NYCTO ceramics 10 , 11 . Such dielectric behavior is similar to that reported in Na 1/2 Sm 1/2 Cu 3 Ti 4 O 12 ceramics 30 . In the current work, the temperature coefficients of ε′ at 1 kHz for the NY9h and NY15h ceramics were evaluated.…”
A modified sol-gel method was used to successfully produce Na1/2Y1/2Cu3Ti4O12 ceramics with high dielectric permittivity. The dielectric permittivity of Na1/2Y1/2Cu3Ti4O12 ceramics reaches values larger than 104 at room temperature and 1 kHz. Moreover, these ceramics exhibit two distinct thermally induced dielectric relaxations over a broad temperature range. The loss tangent is indeed small, ~0.032–0.035. At low temperatures, dielectric relaxation was attributed to the oxygen vacancy effect, while at high temperatures, it was attributed to grain boundary and sample-electrode contact effects. Our calculations revealed that Y and Na ions are likely to occupy Ca and Cu sites, respectively. As a result, other Cu related phases, especially CuO, were observed at the grain boundaries. Based on our analysis, there is a charge compensation between Na and Y ions in Na1/2Y1/2Cu3Ti4O12. Additionally, the Cu+ and Ti3+ states observed in our XPS study originate from the presence of an oxygen vacancy in the lattice. Last, the primary cause of the enormous dielectric permittivity of Na1/2Y1/2Cu3Ti4O12 ceramics primarily comes from the internal barrier layer capacitor effect.
“…Based on our electron density analysis, the charges of Cu and Ti tend to be reduced, whereas the oxidation state of Ta remains unchanged when V o is present in the NYCTTaO lattice. This was also observed for the Na 1/2 Sm 1/2 Cu 3 Ti 4 O 12 [ 45 ] and Na 1/3 Sm 1/3 Ca 1/3 Cu 3 Ti 4 O 12 [ 46 ]. Fig.…”
Section: Resultssupporting
confidence: 65%
“…Next, the most favorable sites for Na + doping ions were considered. For Na 1/2 Sm 1/2 Cu 3 Ti 4 O 12 [ 45 ], Na is likely to occupy Cu sites. Therefore, in the current study, Na and Y ions occupy the Cu and Ca sites, respectively.…”
“…It is anticipated that in the not-too-distant future, the basis for the development of energy storage and memory devices will involve the use of giant dielectric materials that have a high dielectric permittivity (ε′). Having a large ε′, CaCu 3 Ti 4 O 12 (CCTO) and its associated ACu 3 Ti 4 O 12 (ACTO) (A = Y 2/3 , Na 1/2 Sm 1/2 , Cd, Na 1/3 Cd 1/3 Y 1/3 , and Na 1/3 Cd 1/3 Bi 1/3 ) are favored by researchers due to their exceptional temperature stability and frequency stability. − These properties are of utmost importance for developing new technologies for electronic devices. Simple oxide systems such as oxide- and TiO 3 -based ceramics have exhibited a good prospect to be employed as indispensable parts of our home appliances, − for example, as capacitors, varistors, and sensors.…”
A solid-state reaction was performed to create Li1/2Y1/2Cu3Ti4O12, a ceramic
with a very high dielectric constant. The crystal structure of the
ceramic samples belongs to the Im3 space group. Impurity
phases such as CuO and TiO2 have been identified. A dielectric
constant of approximately 4.70–5.00 × 103 and
a low loss tangent of 0.091–0.126 were obtained from our sintered
Li1/2Y1/2Cu3Ti4O12 (LYCTO) ceramics. Impedance spectroscopy results showed the ceramic
microstructure to be electrically heterogeneous. From our electron
density analysis, the oxygen vacancy in the LYCTO lattice is associated
with the observation of the Cu+ and Ti3+ ions.
Finally, significantly divergent values between R
g and R
gb and between E
g and E
gb indicate
that an internal barrier layer capacitor contributes significantly
to this ceramic’s enormous dielectric properties.
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