A Teaching-Learning Framework for Materials Characterization

“Materials Characterization” is a broad discipline that plays a pivotal role in various scientific sectors and requires diversified training to provide learners with the necessary tools and skills for the investigation of materials’ structure, microstructure, and properties. This study puts forward a comprehensive framework aimed at providing undergraduate STEM students with a wide range of competencies for material characterization. These include acquiring the essential theoretical knowledge of key characterization methods, the ability to construct experimental plans, the skills needed for sample preparation, and the aptitude to generate, analyze, and interpret data. By combining various strategies and pedagogical tools, the framework aims to facilitate self-directed and self-determined learning, allowing students to shape their educational journey and explore areas of personal interest within the discipline. Furthermore, the framework incorporates diversified approaches aimed at developing research proficiency and the ability to communicate research outcomes, both within conference contexts and through report formats resembling publications. The findings demonstrate the promising prospect that undergraduate students have the capacity to acquire the methodologies of scientists and to produce work of comparable quality. This study testifies the considerable potential that lies in engaging enthusiastic and capable students in scientific research and fostering the early development of future researchers

A Teaching-Learning Framework for Materials Characterization

“Materials Characterization” is a broad discipline that plays a pivotal role in various scientific sectors and requires diversified training to provide learners with the necessary tools and skills for the investigation of materials’ structure, microstructure, and properties. This study puts forward a comprehensive framework aimed at providing undergraduate STEM students with a wide range of competencies for material characterization. These include acquiring the essential theoretical knowledge of key characterization methods, the ability to construct experimental plans, the skills needed for sample preparation, and the aptitude to generate, analyze, and interpret data. By combining various strategies and pedagogical tools, the framework aims to facilitate self-directed and self-determined learning, allowing students to shape their educational journey and explore areas of personal interest within the discipline. Furthermore, the framework incorporates diversified approaches aimed at developing research proficiency and the ability to communicate research outcomes, both within conference contexts and through report formats resembling publications. The findings demonstrate the promising prospect that undergraduate students have the capacity to acquire the methodologies of scientists and to produce work of comparable quality. This study testifies the considerable potential that lies in engaging enthusiastic and capable students in scientific research and fostering the early development of future researchers

Crystal Chemistry and Magnetic Properties of Gd-Substituted Aurivillius-Type Bi₅FeTi₃O₁₅ Ceramics

Aurivillius-phase ferroelectrics can be turned into multiferroic materials by incorporating magnetic ions. The four-layer Aurivillius-type system Bi₅FeTi₃O₁₅ is well-known to show a strong magnetoelectric effect; however, much controversy exists on its magnetic state and the possible multiferroicity at room temperature. In this paper, we report a detailed investigation on the interconnections between crystal chemistry and magnetic properties of Bi₅FeTi₃O₁₅ ceramics chemically modified by the A-site gadolinium substitution. The structural studies showed that all Bi_5–<i>x</i>Gd_<i>x</i>FeTi₃O₁₅ (0 ≤ <i>x</i> ≤ 1) samples adopt the polar orthorhombic space group symmetry <i>A</i>2₁<i>am</i> at room temperature. The unit cell volume and the orthorhombic distortion decrease alongside the reduction of octahedral tilts by increasing the amount of Gd added. The decrease in tilting distortion of the [Ti/Fe]­O₆ octahedra was further evidenced by the suppression of the Raman A₁[111] tilt mode at 233 cm^–1. By using superconducting quantum interference and vibrating sample magnetometry, it was demonstrated that all the ceramics are paramagnetic from 5 K up to 700 K. It was thus concluded that the A-site substitution of Bi₅FeTi₃O₁₅ with magnetic Gd ions brings about a slight structural relaxation of the parental orthorhombic lattice, but it is not an effective way to induce multiferroic properties in the Aurivillius compound. We suggest that the room-temperature (ferri/ferro/antiferro-) magnetism in Bi₅FeTi₃O₁₅ previously reported in the literature might be due to the presence of magnetic impurities or local short-range magnetic ordering formed during material processing under different conditions

Relaxor behavior and photocatalytic properties of BaBi2Nb2O9

Lead‐free Aurivillius phase BaBi2Nb2O9 powders were prepared by solid‐state reaction. Ferroelectric measurements on BaBi2Nb2O9 (BBNO) ceramics at room temperature provided supporting evidence for the existence of polar nanoregions (PNRs) and their reversible response to an external electric field, indicating relaxor behavior. The photocatalytic degradation of Rhodamine B reached 12% after 3 hours irradiation of BBNO powders under simulated solar light. Silver (Ag) nanoparticles were photochemically deposited onto the surface of the BBNO powders and found to act as electron traps, facilitating the separation of photoexcited charge carriers; thus, the photocatalytic performance was significantly improved. The present study is the first examination of the photochemical reactivity of a relaxor ferroelectric within the Aurivillius family with PNRs