Can I read Singlet ground state in the spin-$1/2$ weakly coupled dimer compound NH$ 4$[(V$ 2$O$ 3$)$ 2$(4,4$^\prime$-$bpy$)$ 2$(H$ 2$PO$ 4$)(PO$ 4$)$ 2$]$\cdot$0.5H$ 2$O on EtoBox?

Singlet ground state in the spin-$1/2$ weakly coupled dimer compound NH$ 4$[(V$ 2$O$ 3$)$ 2$(4,4$^\prime$-$bpy$)$ 2$(H$ 2$PO$ 4$)(PO$ 4$)$ 2$]$\cdot$0.5H$ 2$O by Arjun, U.; Kumar, V.; Anjana, P. K.; Thirumurugan, A.; Sichelschmidt, J.; Mahajan, A. V.; Nath, R. is a scholarly article available to read on EtoBox.

What is Singlet ground state in the spin-$1/2$ weakly coupled dimer compound NH$ 4$[(V$ 2$O$ 3$)$ 2$(4,4$^\prime$-$bpy$)$ 2$(H$ 2$PO$ 4$)(PO$ 4$)$ 2$]$\cdot$0.5H$ 2$O about?

We present the synthesis and a detailed investigation of structural and magnetic properties of polycrystalline NH$_4$[(V$_2$O$_3$)$_2$(4,4$^\prime$-$bpy$)$_2$(H$_2$PO$_4$)(PO$_4$)$_2$]$\cdot$0.5H$_2$O by means of x-ray diffraction, magnetic susceptibility, electron spin resonance, and $^{31}$P nuclear magnetic resonance measurements. Temperature dependent magnetic susceptibility could be described well using a weakly coupled spin-$1/2$ dimer model with an excitation gap $\Delta/k_{\rm B}\simeq 26.1$ K between the singlet ground state and triplet excited states and a weak inter-dimer exchange coupling $J^\prime/k_{\rm B} \simeq 4.6$ K. A gapped chain model also describes the data well with a gap of about 20 K. The ESR intensity as a function of temperature traces the bulk susceptibility nicely. The isotropic Land$\acute{\rm e}$ $g$-factor is estimated to be about $g \simeq 1.97$, at room temperature. We are able to resolve the $^{31}$P NMR signal as coming from two inequivalent P-sites in the crystal structure. The hyperfine coupling constant between $^{31}$P nucleus and V$^{4+}$ spins is calculated to be $A_{\rm hf}(1) \simeq 2963$ Oe/$\mu_{\rm B}$ and $A_{\rm hf}(2) \simeq 1466$ O

Author

Arjun, U.; Kumar, V.; Anjana, P. K.; Thirumurugan, A.; Sichelschmidt, J.; Mahajan, A. V.; Nath, R.

Published

2017

Language

EN