Stripe Order and Magnetic Transitions in La(2-x)Sr(x)NiO(4)

TL;DR

This study investigates magnetic order and spin reorientation phenomena in stripe-ordered La(2-x)Sr(x)NiO(4) across multiple doping levels, revealing an intrinsic spin transition characteristic of the stripe phase.

Contribution

It provides detailed neutron diffraction analysis showing spin reorientation in La(2-x)Sr(x)NiO(4) for various doping levels, highlighting its intrinsic nature.

Findings

Spin reorientation occurs in all studied compositions.

Spin axes rotate from an angle to the stripe direction at specific temperatures.

The spin transition is intrinsic to the stripe phase.

Abstract

Magnetic order has been investigated in stripe-ordered La(2-x)Sr(x)NiO(4) (x = 0.275, 0.37, 0.4) by d.c. magnetization and by polarized- and unpolarized-neutron diffraction. In the magnetically ordered phase, all three compositions exhibit a magnetic transition consistent with a spin reorientation in the ab plane. For x = 0.37, the spin axes rotate from an angle of 37.7 +/- 0.3 degrees to the stripe direction at 71 K, to 52.3 +/- 0.2 degrees at 2 K. The x = 0.275 and 0.4 compounds were found to undergo a similar spin reorientation. A spin reorientation has now been observed to occur for five different doping levels in the range x = 0.275 - 0.5, suggesting that this spin transition is an intrinsic property of the stripe phase.