KONSTAN - JURNAL FISIKA DAN PENDIDIKAN FISIKA

UV-Vis Spectroscopic Analysis for Band Gap Determination of Cobalt-Doped Magnetite (Fe2.5Co0.5O4) Nanoparticles Derived from Natural Iron Sand

Dian Wijaya Kurniawidi — 2026-05-21

Doping is an effective approach to altering the electronic and structural properties of a material, thereby influencing its optical and magnetic characteristics. This study successfully synthesized and characterized cobalt-doped magnetite (Fe_2.5Co_0.5O₄) nanoparticles from natural iron sand using the coprecipitation method. The main objective was to evaluate the optical properties of the synthesized material through UV-Vis spectral analysis and to compare the band gap energy values using three approaches: the Tauc method (direct and indirect transitions), the Kubelka–Munk method, and the Urbach energy calculation as an indicator of structural disorder. The characterization results revealed that the incorporation of Co²⁺ ions into the magnetite structure induced significant changes in the absorption patterns, including the emergence of new absorption peaks and a redshift in wavelength. The obtained band gap values were 3.71 eV (Tauc-direct), 2.18 eV (Tauc-indirect), and 2.33 eV (Kubelka–Munk), confirming the presence of two types of optical transitions. Furthermore, the relatively low Urbach energy (0.07138 eV) indicated that the crystal structure remained well-preserved despite the modifications induced by doping. This study highlights the importance of employing multi-method approaches for reliable optical characterization and demonstrates that Fe_2.5Co_0.5O₄ materials derived from local resources possess promising potential for photocatalytic and optoelectronic applications.

Exploring Science Students’ Creativity and Critical Thinking Skills through Fluid Learning

Khoiro Mahbubah — 2026-05-27

Amid rapid technological Development, creative thinking skills are highly sought after. Creativity enables individuals to generate new ideas, find innovative solutions in complex situations, and adapt more easily to change. This study aims to determine the level of creative thinking skills of prospective science teachers through four primary indicators: flexibility of thinking, fluency in generating ideas, originality of ideas, and the ability to elaborate ideas. This study used a quantitative descriptive approach and involved 20 prospective science teachers at Lamongan Islamic University. The research instrument was a Likert-scale questionnaire. Data were analyzed by assigning a score to each statement, followed by descriptive statistics including averages, frequency distributions, percentages, and standard deviations. Furthermore, students' abilities were categorized by score, and creative thinking skills received the highest score on the fluency indicator (81.20%), while flexibility received the lowest (53.40%). For critical thinking skills, indicators of giving building (55.55%) and organizing strategies and explanations of inference skills are in the low category (54.70%). This condition is caused by students' difficulties in generating new ideas or generating various alternative solutions when facing a problem. Therefore, the results of this study are expected to inform educators in developing learning strategies that stimulate the creativity of prospective science teachers, for example, through learning modules that train 21st-century skills, discovery-based approaches, or the use of media that encourage students to be more daring in their creations.

Improving Physics Learning Activities and Outcomes Using the Problem-Based Learning Model Assisted by Blooket Media in High School Students

Nilta Wahyuni — 2026-05-21

The activities and learning outcomes of physics students in class X of high school are still relatively low due to the lack of student involvement and the use of interesting learning modes. The Problem-Based Learning (PBL) learning model, based on problem solving, if supported by interactive media such as Blooket, will have the
potential to increase student participation and understanding. This study aims to describe the improvement of students' physics learning activities and outcomes using the Problem-Based Learning (PBL) learning model assisted by Blooket media at SMA Negeri 5 Jember. The respondents in this study were students in class X 5 at SMA Negeri 5 Jember. This research uses Classroom Action Research (PTK), which is carried out in two cycles. In this case, each cycle consists of four stages, namely planning, implementation, observation, and reflection. The results of cycle I are used as a benchmark for the implementation of cycle II. Where the implementation of cycle II was carried out to overcome the weaknesses that existed in cycle I. The results of the study showed that the use of the Problem-Based Learning (PBL) learning model assisted by Blooket media experienced an increase in learning outcomes from cycle I to cycle II by 0.53 to 0.73. Then, in the analysis of learning activities in cycle I to cycle II, the percentage increased from the active category to very active, with an average of cycle I of 74.58% and cycle II of 91.67%. Therefore, it can be concluded that the use of the Problem-Based Learning (PBL) learning model assisted by Blooket media can improve students' physics learning activities and outcomes.