Chemical Pressure Tuning of Magnetic Coupling in the La1.4Sr1.6Mn2O7 Bilayered Manganite

TL;DR

This study investigates how chemical pressure, induced by substituting Sr with Ca in La1.4Sr1.6Mn2O7, alters magnetic coupling from ferromagnetic to antiferromagnetic, revealing effects on orbital order via neutron diffraction.

Contribution

It demonstrates the direct impact of chemical pressure on magnetic coupling and orbital order in bilayered manganites using neutron diffraction.

Findings

Magnetic coupling changes from ferromagnetic to antiferromagnetic with increased Ca content.

Orbital order of Mn ions is affected similarly by chemical and external pressure.

Neutron diffraction reveals temperature-dependent magnetic and orbital modifications.

Abstract

In this paper the effect of the chemical pressure induced by the Sr replacement for Ca in the La1.4Sr1.6Mn2O7 lattice is directly probed by means of neutron diffraction as a function of temperature. The results show a progressive change of the magnetic coupling from ferromagnetic to antiferromagnetic by increasing the Ca content,. indicating that the orbital order of the Mn ions is affected in the same way by the application of an external pressure and by the chemical pressure.