Neutron diffraction studies on magnetic properties of Ca5Ni4V6O24

Abstract The temperature dependent neutron powder diffraction (NPD) and magnetization measurements of vanadium based garnet Ca 5 Ni 4 V 6 O 24 (CNVO) have been performed to explore its crystal and magnetic structures. The magnetization results illustrate two magnetic anomalies at 7 and 4 K. The Rietveld analysis of room temperature x-ray diffraction and NPD data confirms its Ia -3 d crystal structure. The temperature dependent NPD shows the emergence of magnetic reflections below 7 K whose intensity keeps on increasing with decreasing temperature down to 1.5 K. The crystal structure remains cubic down to 1.5 K. Rietveld analysis reveals that below 7 K, the Ni moments in CNVO undergo a commensurate collinear A-type antiferromagnetic ordering with propagation vector k =(0,0,0) and the per site ordered moment of Ni 2+ is 1.69±0.05 μ B . Absence of any additional magnetic or nuclear reflections below 4 K confirms that the nuclear and magnetic structures remain invariant across the 4 K magnetic anomaly.