Complex magnetic ordering in CeGe1.76 studied by neutron diffraction

TL;DR

This study investigates the complex magnetic phase transitions in CeGe1.76 using neutron diffraction, revealing multiple magnetic states and ordering phenomena at low temperatures.

Contribution

It provides detailed neutron diffraction analysis of magnetic ordering and transitions in CeGe1.76, highlighting new incommensurate and commensurate magnetic structures.

Findings

Magnetic transition at T_N = 7 K to incommensurate structure

Lock-in transition at T_LI = 5 K to commensurate structure

Additional magnetic Bragg peaks below T* = 4 K indicating complex magnetic states

Abstract

Neutron diffraction measurements on a single crystal of CeGe1.76 reveal a complex series of magnetic transitions at low temperature. At T_N = 7 K, there is a transition from a paramagnetic state at higher temperature to an incommensurate magnetic structure characterized by a magnetic propagation vector (0 0 tau) with tau approx. 1/4 and the magnetic moment along the a axis of the orthorhombic unit cell. Below T_LI = 5 K, the magnetic structure locks in to a commensurate structure with tau = 1/4 and the magnetic moment remains along the a axis. Below T* = 4 K, we find additional half-integer and integer indexed magnetic Bragg peaks consistent with a second commensurately ordered antiferromagnetic state.