Neutron Scattering Studies on Magnetic Structure of the Double-Layered Manganite La_{2-2x}Sr_{1+2x}Mn_2O_7 ($0.30 \leq x \leq 0.50$)

TL;DR

This study uses neutron scattering to map the magnetic phases of La_{2-2x}Sr_{1+2x}Mn_2O_7 across a range of compositions, revealing transitions from ferromagnetic to antiferromagnetic structures at different doping levels.

Contribution

It provides a comprehensive magnetic phase diagram of La_{2-2x}Sr_{1+2x}Mn_2O_7 using systematic neutron diffraction, highlighting the evolution of magnetic structures with doping.

Findings

Planar ferromagnetic structure for 0.32 ≤ x ≤ 0.38

Finite canting angle appears around x ≈ 0.40

A-type antiferromagnet at x=0.48

Abstract

Systematic powder diffraction studies have been carried out to establish the magnetic phase diagram of La_{2-2x}Sr_{1+2x}Mn_2O_7 (LSMO327) in a wide hall concentration range ($0.30 \leq x \leq 0.50$), using the HERMES diffractometer. LSMO327 exhibits a planar ferromagnetic structure for $0.32\leq x\leq 0.38$ at low temperatures. A finite canting angle between planar magnetic moments on neighboring planes starts appearing around $x\sim 0.40$ and reaches 180$^{\circ}$ (A-type antiferromagnet) at x=0.48. At x=0.30, on the other hand, the magnetic moments are aligned parallel to the c-axis.