Exploration of crystal field level scheme of NdZnAl11O19

Exotic non-trivial magnetic behaviour has been recently reported in geometrically frustrated systems. In these systems, competing spin interactions leads to strong quantum fluctuations and prevent long range ordering (LRO) down to low temperatures. 2D triangular antiferromagnets (TAFM) is one of the prototypes to study frustration, as it has large degeneracy of ground states. Especially, rare-earth based TAFM having strong anisotropic magnetic interactions caused by spin orbit coupling and crystal electric field (CEF) effect, provides a platform for realising intriguing quantum phenomena. In determining the exotic magnetic ground state of these system, exchange and dipolar interactions, along with, crystal field scheme plays a vital role. Among these, crystal field is mainly responsible for governing the underlying physics. In respect to this, Nd based system is interesting to study. Nd3+ is a Kramer ion (J = 9/2) and having strong magnetic anisotropy. The 4I9/2 Nd3+ multiplets splits into five Kramer doublets due to CEF effect. To comprehend the magnetic properties and to quantitatively assess the magnetic interactions in NdZnAl11O19, it is essential to have knowledge about CEF level and single ion anisotropy.