Structural and magnetic properties of spin-\(1/2\) dimer compound Cu\(_2\)(IPA)\(_2\)(DMF)(H\(_2\)O) with a large spin gap

• Published in: arXiv.org
• Main Authors: Thamban, S, Arjun, U, Padmanabhan, M, Nath, R
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 17.03.2017
• Subjects: Copper; Dimers; Hydrothermal reactions; Ligands; Magnetic permeability; Magnetic properties; Organometallic compounds; Route selection; Single crystals; Specific heat; Structural analysis; Temperature dependence; X-ray diffraction
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1703.05896

We present the synthesis and a detailed investigation of structural and magnetic properties of metal-organic compound Cu\(_2\)(IPA)\(_2\)(DMF)(H\(_2\)O) by means of x-ray diffraction, magnetization, and heat capacity measurements. Single crystals of the title compound were synthesized by judicious selection of organic ligand and employing a selective hydrothermal reaction route. It crystallizes in an orthorhombic structure with space group \(Cmca\). The structural analysis revealed that two Cu\(^{2+}\) ions are held together by the organic component (-O-C-O-) in a square paddle-wheel to form spin dimers which are aligned perpendicular to each other and are further coupled through organic ligands (isophthalic acid) forming two-dimensional layers. Temperature dependent magnetic susceptibility \(\chi(T)\) could be described well using spin-\(1/2\) dimer model. The spin susceptibility \(\chi_{\rm spin} (T)\) shows an exponential decrease in the low temperature region, below the broad maximum, confirming the singlet ground state with a large spin gap of \(\Delta/k_{\rm B} \simeq 409\)~K. The heat capacity \(C_{\rm p}\) measured as a function of temperature also confirms the absence of magnetic long-range-order down to 2~K.