Majumder, M. and Ghoshray, K. and Ghoshray, A. and Pal, A. and Awana, V. P. S. (2013) Local electromagnetic properties of magnetic pnictides: a comparative study probed by NMR measurements. Journal of Physics: Condensed Matter, 25 (19). pp. 196002-196012. ISSN 0953-8984

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Abstract

As-75 and P-31 NMR studies are performed in PrCoAsO and NdCoPO respectively. The Knight shift data in PrCoAsO indicate the presence of an antiferromagnetic interaction between the 4f moments along the c axis in the ferromagnetic state of Co 3d moments. We propose a possible spin structure in this system. The As-75 quadrupolar coupling constant, nu(Q), increases continuously with decrease of temperature and is found to vary linearly with the intrinsic spin susceptibility, K-iso. This indicates the possibility of the presence of a coupling between charge density and spin density fluctuations. Further, the P-31 NMR Knight shift and spin-lattice relaxation rate (1/T-1) in the paramagnetic state of NdCoPO indicate that the differences of LaCoPO and NdCoPO from SmCoPO are due to the decrement of the interlayer separation and not due to the moments of the 4f electrons. The nuclear spin-lattice relaxation time (T-1) in NdCoPO shows weak anisotropy at 300 K. Using the self-consistent renormalization (SCR) theory of itinerant ferromagnets, it is shown that in the ab plane, the spin fluctuations are three-dimensional ferromagnetic in nature. From SCR theory the important spin-fluctuation parameters (T-0, T-A, (F) over bar (1)) are evaluated. The similarities and dissimilarities of the NMR results in As and P based systems with different rare earths are also discussed.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier.
Subjects:	Applied Physics/Condensed Matter
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	09 Jul 2020 11:06
Last Modified:	09 Jul 2020 11:06
URI:	http://npl.csircentral.net/id/eprint/3144

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