Spin density functional study on magnetism of potassium loaded Zeolite A

TL;DR

This study uses density-functional calculations to explore how potassium-loaded Zeolite A exhibits ferromagnetism, revealing that potassium electrons in confining potentials are responsible for spin polarization, which depends on atomic configuration.

Contribution

It demonstrates that non-magnetic elements can exhibit ferromagnetism through confining potentials and p-states, providing a systematic understanding of spin polarization in this system.

Findings

Potassium-loaded Zeolite A can exhibit ferromagnetism despite containing only non-magnetic elements.

The spin polarization is primarily due to potassium 4s electrons in p-states within a confining potential.

Magnetic moments are highly sensitive to the atomic arrangement of potassium atoms.

Abstract

In order to clarify the mechanism of spin polarization in potassium-loaded zeolite A, we perform {\em ab initio} density-functional calculations. We find that (i) the system comprising only non-magnetic elements (Al, Si, O and K) can indeed exhibit ferromagnetism, (ii) while the host cage makes a confining quantum-well potential in which $s$- and $p$-like states are formed, the potassium-4$s$ electrons accommodated in the p-states are responsible for the spin polarization, and (iii) the size of the magnetic moment sensitively depends on the atomic configuration of the potassium atoms. We show that the spin polarization can be described systematically in terms of the confining potential and the crystal field splitting of the p-states.