2026, Vol.36, No.2

Journal of the Korean Crystal Growth and Crystal Technology 2024 KCI Impact Factor : 0.2

pISSN : 1225-1429 / eISSN : 2234-5078
https://journal.kci.go.kr/jkcgct

Understanding emission color tunability in lead-free zero-dimensional (0D) metal halides is essential for the rational design of eco-friendly luminescent materials. In this review, we summarize recent progress in correlating local octahedral distortion with photoluminescence behavior in Sb3+-doped Cs3LnCl6 (Ln = La, Gd, Y, Lu) and related systems through Rietveld refinement analysis. Although chemical substitution with smaller Ln3+ ions induces lattice contraction, accumulated studies consistently show that emission peak shifts do not directly scale with unit cell volume. Instead, growing evidence indicates that the dispersion of Sb-Cl bond lengths within SbCl6 octahedra plays a dominant role in emission tuning. Key distortion descriptors, including the distortion index (D), exhibit clear correlations with emission energy and spectral bandwidth. We further compare chemical pressure effects with external pressure studies, revealing a unified structural mechanism governing emission tuning in Cs2ZrCl6:Sb3+ composition. Electronic structure analyses confirm that the SbCl6 coordination environment influences both the band-edge positions and the stabilization of self-trapped excitons (STEs). This review provides a quantitative framework for using Rietveld refinement as a powerful tool to elucidate structure–property relationships in lead-free luminescent halides and outlines future design strategies based on local coordination control.

This study defines eccentricity-based geometric repetition as a system of design variables—eccentric displacement (e), rotational phase angle (θ), and repetition level (n)—and proposes a design methodology applicable to contemporary jewelry design. An eccentric repetitive structure integrating these variables was analyzed to identify their structural roles: eccentric displacement (e) induces spatial expansion and asymmetry, rotational phase angle (θ) controls directional variation and arrangement, and repetition level (n) generates spatial depth and density. Based on this framework, an open C-type model and a design process based on variable integration were developed, and structural stability and wearability were examined through 3D CAD modeling. The results demonstrate that the eccentric structure functions as a controllable and reproducible form-generation system integrating asymmetry and order, and suggest its potential as a design methodology for contemporary jewelry design.

This study investigated changes in the physical and mechanical properties of polypropylene (PP) composites reinforced with sCMF (silica-coated cellulose microfiber) and lignocellulose to develop eco-friendly bioplastics suitable for injection-molded household goods, films, and trays. The total cellulose content was fixed at 30 wt%, while portions of conventional cellulose were replaced with sCMF and lignocellulose. Density, melt flow rate (MFR), tensile strength, and impact strength were measured after extrusion and injection molding processes. The density values were approximately 1.03 g/cm³ for most samples, while the CNL5T sample containing Talc increased to 1.07 g/cm³. The MFR decreased from 4.8 g/10 min for the control sample (CLB30) to 2.5–4.5 g/10 min for the modified samples. Tensile strength increased from 19.8 MPa for CLB30 to 20.8–23.2 MPa, with CNL10 showing the highest value. Impact strength remained in the range of 45–51 J/m for most samples, similar to CLB30 (46 J/m), whereas CNL5T decreased to 35 J/m. These results indicate that the physical and mechanical properties of cellulose-based PP composites can be controlled by the type and substitution ratio of modified cellulose-based fillers and auxiliary additives.