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2. Tunable electrocaloric effect in lead scandium tantalate through calcium dopingYouri Dilan Nouchokgwe Kamgue, Natalja Stanislavovna Fjodorova, Veronika Kovacova, Ivana Goričan, Nejc Suban, Silvo Drnovšek, Matej Šadl, Uroš Prah, Hana Uršič Nemevšek, Emmanuel Defay, 2026, izvirni znanstveni članek Ključne besede: electrocaloric cooling, electrocaloric effect
Objavljeno v DiRROS: 24.06.2026; Ogledov: 257; Prenosov: 161
 Celotno besedilo (1,39 MB)
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3. Microstructural engineering of sodium potassium niobate for enhanced and temperature-stable electromechanical responseAndraž Bradeško, Janina Roknić, Nejc Suban, Katarina Žiberna, Silvo Drnovšek, Brigita Kmet, Aadil Abass Shah, Marko Robić, Hana Uršič Nemevšek, Tadej Rojac, Andreja Benčan, Barbara Malič, 2026, izvirni znanstveni članek Povzetek: The development of high-performance lead-free piezoelectrics is a critical step toward sustainable electronic components, yet matching the electromechanical stability over external variables, such as temperature, of lead-based standards remains a significant challenge. This study investigates the synergistic effects of Ti-doping and K5.4Cu1.3Ta10O29 (KCT) co-modification on the structural and functional properties of (K0.5Na0.5)NbO3 (KNN) ceramics. Co-modification significantly enhances both electromechanical coupling and the mechanical quality factor, parameters essential for ultrasonic transducer applications. A comparative analysis of the ferroelectric behavior reveals that these modifications establish a stable internal bias field leading to the hardening of piezoelectric properties. Interestingly, the samples modified solely by Ti exhibit a stronger internal bias field than the Cu-containing co-modified samples, a phenomenon further explored through domain imaging. When benchmarked against commercial hard PZT, the optimized KNN-Ti-KCT ceramic demonstrates comparable thermal stability in the room-temperature to 100°C range. Although a trade-off exists between peak piezoelectric coefficients and environmental impact, these results highlight the potential of tailored KNN ceramics as reliable lead-free alternatives for high-temperature electromechanical devices.
Ključne besede: electronic ceramics, piezoelectricity, electromechanical stability
Objavljeno v DiRROS: 25.05.2026; Ogledov: 354; Prenosov: 399
Celotno besedilo (5,56 MB)
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4. Impact of sintering temperature on structural, microstructural and electrical properties of screen-printed ▫$0.7Pb(Fe_{0.5}Nb_{0.5})O_3–0.3BiFeO_3$▫ thick filmsIvana Goričan, Andreja Benčan, Silvo Drnovšek, Antonio Iacomini, Nejc Suban, Brigita Kmet, Uroš Prah, Tadej Rojac, Hana Uršič Nemevšek, 2026, izvirni znanstveni članek Povzetek: (1–x)Pb(Fe0.5Nb0.5)O3–xBiFeO3 (PFN–100xBFO) ceramics exhibit versatile functional properties, from ferroelectric, relaxor to antiferroelectric behaviour, but have not yet been prepared as ceramic thick films, which are the key to miniaturization of electronic components. In this work, screen-printed thick films of PFN–30BFO were prepared on gold-coated alumina substrates and sintered at 800 °C, 850 °C and 930 °C. The impact of the sintering temperature on their properties was studied. The films annealed at 930 °C exhibited excessive electrical conductivity. In contrast, well developed polarization versus electric field hysteresis loops were observed in the films treated at 800 °C and 850 °C. The films annealed at 800 °C had the smallest grain size and dielectric permittivity values but achieved the highest dielectric breakdown strength. The findings of this study highlight the potential of PFN–30BFO screen-printed films, sintered at 800 °C, for use in miniaturized high-voltage electronic devices.
Ključne besede: thick films, electronic ceramics, sintering temperature
Objavljeno v DiRROS: 20.04.2026; Ogledov: 441; Prenosov: 365
Celotno besedilo (12,02 MB)
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5. Investigation of ceramic powders using piezoresponse force microscopyNejc Suban, Silvo Drnovšek, Hana Uršič Nemevšek, 2026, izvirni znanstveni članek Povzetek: Piezoresponse force microscopy (PFM) is a widely used technique for probing the piezoelectric and ferroelectric properties of ceramic materials at the nanoscale. However, its application to ceramic powders remains challenging due to the irregular non-flat shape of the powders. In this study, an approach for PFM analysis of ceramic powders is presented, where ceramic powders are embedded in polymer resin and polished to achieve flat surface for PFM imaging. The approach is demonstrated on ferroelectric PbZr0.53Ti0.47O3 (PZT) and 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 (PMN-35PT) powders. PFM imaging reveals the piezoelectricity within the powder particles and localises the ferroelectric domains within them, while the PFM switching spectroscopy experiment is used to observe the domain switching behavior.
Ključne besede: ceramic powder, piezoresponse force microscopy
Objavljeno v DiRROS: 17.02.2026; Ogledov: 595; Prenosov: 443
Celotno besedilo (2,80 MB)
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6. Improvement of piezocatalytic performance of ▫$Na_{0.5}Bi_{0.5}TiO_3$▫ perovskite using K doping for efficient rhodamine B degradationSalma Ayadh, Salma Touili, M'barek Amjoud, Daoud Mezzane, Mohamed Gouné, Jaafar Ghanbaja, Manal Benyoussef, Hana Uršič Nemevšek, Nejc Suban, Zdravko Kutnjak, Mimoun El Marssi, 2025, izvirni znanstveni članek Ključne besede: piezocatalysis, sodium bismuth titanate, potassium doping, piezo-degradation
Objavljeno v DiRROS: 19.01.2026; Ogledov: 560; Prenosov: 141
Celotno besedilo (2,82 MB)
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7. Ferroelectric ▫$KNbO_3$▫ nanoplatelets for thermally driven pyrocatalytic hydrogen evolution and dye degradationSalma Touili, Bouchra Asbani, Youness Hadouch, Nejc Suban, Hana Uršič Nemevšek, Zdravko Kutnjak, Brigita Rožič, Mimoun El Marssi, 2026, izvirni znanstveni članek Povzetek: Day and night shift-induced thermal cycling offers a promising route toward free energy for green hydrogen production and dye degradation. Pyroelectric materials make this possible by converting temperature fluctuations into electrical charges that drive water splitting catalytic reactions and produce hydrogen fuel. Herein, we demonstrate an efficient pyrocatalytic hydrogen evolution reaction and Rhodamine B (RhB) degradation using ferroelectric potassium niobate (KNbO3) perovskite nanoplatelets (KN-np) with an orthorhombic phase. Under thermal cycling between 20 and 50 °C, KN-np produced a high hydrogen yield of 680 μmol·g–1 over 30 thermal cycles, with an average hydrogen generation rate of approximately 22.67 μmol g–1 per thermal cycle. Besides, KN-np pyrocatalytic activity enabled efficient degradation of the RhB dye up to 84 % after only 16 cycles with a high kinetic rate constant of 0.11 per thermal cycle. Our findings show that the excellent pyroelectric properties of KN-np are at the origin of the catalytic activity enhancement. This work lays the foundation for the future design of pyroelectric materials for clean energy production and environmental remediation.
Ključne besede: pyrocatalysis, nanoplatelets, clean energy production, dye degradation
Objavljeno v DiRROS: 16.01.2026; Ogledov: 689; Prenosov: 640
Celotno besedilo (7,88 MB)
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8. Mikorizacija sadik pred sadnjo za izboljšanje preživetja sadik drevesnih vrst pri pogozdovanju degradiranih območij na Krasu (Poročilo)Nejc Suban, Marijana Vidrih Minić, Boris Rantaša, Matej Kravanja, Andrej Breznikar, Tine Grebenc, 2025, elaborat, predštudija, študija Ključne besede: mikorizacija, glive, simbioza, gomoljike, sadike, hrast, Kras
Objavljeno v DiRROS: 24.12.2025; Ogledov: 728; Prenosov: 0 |
9. Capacitive energy-storage and electromechanical properties of aerosol-deposited ▫$0.5BaZr_{0.2}Ti_{0.8}O_3–0.5Ba_{0.7}Ca_{0.3}TiO_3$▫ filmsSoukaina Merselmiz, Ivana Goričan, Tadej Rojac, Vid Bobnar, Victor Regis de Moraes, Matej Šadl, Val Fišinger, Nejc Suban, Brigita Kmet, Andreja Benčan, Andraž Bradeško, Andrej Debevec, Barbara Malič, Hana Uršič Nemevšek, 2026, izvirni znanstveni članek Ključne besede: electronic ceramics, powder aerosol composition, thin films, ferroelectricity, energy storage, electromechanical properties
Objavljeno v DiRROS: 08.12.2025; Ogledov: 1189; Prenosov: 463
Celotno besedilo (7,28 MB)
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10. Impact of post-deposition curing of graphite thick-film working electrode on the performances of electrochemical sensorsDanjela Kuščer, Barbara Repič, Janez Kovač, Nejc Suban, Hana Uršič Nemevšek, 2025, izvirni znanstveni članek Ključne besede: electrochemical sensors, electrodes, polymers, graphite thick films, surface morphology
Objavljeno v DiRROS: 27.10.2025; Ogledov: 862; Prenosov: 480
Celotno besedilo (4,59 MB)
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