Electrical Response of a Multiferroic Composite Semiconductor Fiber Under a Local Magnetic Field and a Local Temperature Change

Multiferroic composite semiconductor fibers enable non-contact magnetic control but may also operate under spatially nonuniform thermal conditions. This study develops a one-dimensional analytical model for a symmetric CoFe₂O₄/ZnO/CoFe₂O₄ fiber subjected to local magnetic and temperature fields with independently prescribed widths. The model combines piezomagnetic, piezoelectric, pyroelectric, thermoelastic, and semiconductor effects and provides closed-form solutions for the electric potential, electric field, polarization, and electron concentration perturbation. Local magnetic and thermal inputs generate localized potential barriers and wells through distinct pathways. Where the excitation regions overlap, their contributions may reinforce, compete with, or partially cancel each other. The initial electron concentration affects the carrier-screening strength and spatial localization of the electrical response, whereas the layer-thickness ratio influences the competition between piezomagnetic actuation and piezoelectric conversion. An independent finite-element calculation closely reproduces the analytical potential distribution for the baseline case. This study clarifies the interaction between the magnetic and thermal contributions to open-circuit carrier redistribution and provides a field-distribution baseline for future biased, contact-resolved transport analyses of multiferroic micro- and nanostructures.