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<p>The structure, heat capacity, dielectric and magnetodielectric properties of (1–<i>x</i>)SmFeO<sub>3</sub>–<i>x</i>NaNbO<sub>3</sub> (<i>x</i> = 0 – 1) ceramics were studied over wide temperature and frequency ranges. X-ray diffraction and calorimetry data demonstrated the coexistence of two phases; a T–<i>x</i> diagram was constructed, signatures of both characteristic transitions (T<sub>NC</sub> for SmFeO<sub>3</sub> and T<sub>C</sub> for NaNbO<sub>3</sub>) can be identified in compositions with 0.2 ≤ <i>x</i> ≤ 0.6 and shifting toward lower temperatures with increasing NaNbO<sub>3</sub> content. It was found that ε′(<i>f</i>) exhibits typical Maxwell–Wagner dispersion: maximum changes are observed for <i>x</i> = 0 and 0.2 (for <i>x</i> = 0.2: ~ 1573 →  ~ 307; − 80.5%), while for <i>x</i> = 0.4 the dispersion is minimal (− 12.4%). Temperature dependences of ε′(T) at 1&#xa0;kHz reveal local anomalies: ~ 310–315&#xa0;°C for NaNbO<sub>3</sub> and <i>x</i> = 0.4; an additional one — ~ 370&#xa0;°C (<i>x</i> = 0.6–0.8) and a maximum of ~ 410–420&#xa0;°C for NaNbO<sub>3</sub>; for SmFeO<sub>3</sub>, a maximum of ~ 90–100&#xa0;°C is recorded with a subsequent decrease. The frequency dependences of σ<sub>ac</sub>(<i>f</i>) obey Jonscher's law (σ<sub>ac</sub> ≈ σ<sub>dc</sub> + Aω<sup><i>s</i></sup>). Arrhenius plots (1&#xa0;kHz–1&#xa0;MHz) identified windows with different transport mechanisms and effective activation energies. A positive magnetodielectric effect was detected at room temperature (Mc &gt; 0), the amplitude of which increases with <i>x</i>. Taken together, the results indicate that varying <i>x</i> allows for targeted tuning of the frequency-temperature response and loss level.</p>

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Crystal structure, thermodynamic and dielectric properties of the SmFeO3–NaNbO3 composite

  • 期刊论文

  • 发表日期：

    2026年3月18日

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  • Suleiman N. Kallaev,
  • Shamil P. Faradzhev,
  • A. R. Bilalov,
  • Zairbek M. Omarov,
  • Nariman M.-R. Alikhanov,
  • Z. Sh. Pirmagomedov,
  • Kamaludin G. Abdulvakhidov,
  • Abeer Alshoekh

摘要

The structure, heat capacity, dielectric and magnetodielectric properties of (1–x)SmFeO3–xNaNbO3 (x = 0 – 1) ceramics were studied over wide temperature and frequency ranges. X-ray diffraction and calorimetry data demonstrated the coexistence of two phases; a T–x diagram was constructed, signatures of both characteristic transitions (TNC for SmFeO3 and TC for NaNbO3) can be identified in compositions with 0.2 ≤ x ≤ 0.6 and shifting toward lower temperatures with increasing NaNbO3 content. It was found that ε′(f) exhibits typical Maxwell–Wagner dispersion: maximum changes are observed for x = 0 and 0.2 (for x = 0.2: ~ 1573 →  ~ 307; − 80.5%), while for x = 0.4 the dispersion is minimal (− 12.4%). Temperature dependences of ε′(T) at 1 kHz reveal local anomalies: ~ 310–315 °C for NaNbO3 and x = 0.4; an additional one — ~ 370 °C (x = 0.6–0.8) and a maximum of ~ 410–420 °C for NaNbO3; for SmFeO3, a maximum of ~ 90–100 °C is recorded with a subsequent decrease. The frequency dependences of σac(f) obey Jonscher's law (σac ≈ σdc + Aωs). Arrhenius plots (1 kHz–1 MHz) identified windows with different transport mechanisms and effective activation energies. A positive magnetodielectric effect was detected at room temperature (Mc > 0), the amplitude of which increases with x. Taken together, the results indicate that varying x allows for targeted tuning of the frequency-temperature response and loss level.