Akademik Veri Yönetim Sistemi
EUROPEAN PHYSICAL JOURNAL PLUS, cilt.141, sa.5, 2026 (SCI-Expanded, Scopus)
In this study, we rigorously investigate the spin-7/2 Ising Blume-Capel model subjected to randomly distributed single-ion anisotropy within a mean-field framework based on the Bogoliubov variational inequality. The ground-state phase diagram in the (alpha,d/q\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \alpha , d/q $$\end{document}) plane reveals a rich hierarchy of magnetic phases, arising from the competition between the disorder strength alpha\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha $$\end{document} and the crystal field parameter d. At finite temperatures, the system exhibits a complex phase topology characterized by first-and second-order phase transitions, reentrant behavior, and isolated critical points. These features originate from the interplay between thermal fluctuations, anisotropy, and quenched disorder, and are significantly enhanced compared to lower-spin systems. The magnetic response displays multiple magnetization plateaus together with a pronounced multi-loop hysteresis structure, stemming from metastable states associated with the multilevel nature of the spin-7/2 system and strongly amplified by disorder effects. Overall, the results highlight the key role of high spin and quenched disorder in generating rich and nontrivial magnetic behavior.