arXiv subjects

Moumita Nandi

Publications and source records attributed to Moumita Nandi.

4 recordsLinked to original sources

arXiv2026

Colossal magnetostriction effect in rare-earth orthoferrites

Within the entire gamut of magnetostrictive, piezomagnetic, and ferromagnetic shape memory alloy systems, the striction effect is found to vary from a few tens of parts per million to a few percent. Here, we report the observation of an unprecedentedly large magnetic-field-induced lattice strain along the $c$ axis (more than 60-100% at 90 kOe field) in single crystals of orthorhombic $R$FeO$_3$ ($R$ = Dy, Ho) below their spin-reorientation transition temperature $T_{SR}$. However, the striction effect is two orders of magnitude smaller along the $a$ and $b$ axes. Like magnetostriction, the magnetodielectric effect is highly anisotropic and very large along the $c$ axis. Such gigantic striction and dielectric effects along the $c$ axis arise as a result of a magnetic-field-induced first-order structural phase transition which possibly stems from large spin-orbit coupling (and, thereby, enormous magnetocrystalline anisotropy). The observed colossal striction in rare-earth orthoferrites could open new opportunities for applications requiring large, reversible magnetic-field-induced strain.

cond-mat.mtrl-sci↗

arXiv2025

Single crystal growth of 1T-VSe$_2$ by molten salt flux method

VSe$_2$ is a highly promising van der Waals (vdW) material for applications in electronics, spintronics, and optoelectronics. Here, we report single crystal growth of 1T-VSe$_2$ by flux method using eutectic of NaCl/KCl molten salt. The typical size of as-grown VSe$_2$ single crystals is 5 $\times$ 4 $\times$ 0.1~mm$^3$. The elemental composition and homogeneity of the crystals were examined by energy dispersive x-ray spectroscopy, which is consistent with the stoichiometric ratio of VSe$_2$. The crystallographic [001] direction has been determined by x-ray diffraction. Raman measurement confirms that the 1T phase of VSe$_2$ has been formed. Temperature-dependent resistivity measurement exhibits a transition around 104 K due to the formation of the charge density wave phase.

cond-mat.mtrl-sci↗

arXiv2024

Anomalous resistivity upturn in Co intercalated TaS$_2$

Intercalation of magnetic atoms into the van der Waals gaps of layered transition metal dichalcogenides offers an excellent platform to produce exotic physical properties. Here, we report a detailed study of magnetic and electrical transport properties of Co$_{0.28}$TaS$_2$. The temperature dependent resistivity measurements display anomalous upturn below 11 K, which persists in presence of magnetic field even up to 14 T. In the low temperature region, the resistivity upturn exhibits a unique $T^{1/2}$ scaling behavior, which remains unchanged when an external magnetic field is applied. The $T^{1/2}$ dependence of resistivity upturn is the hallmark of non-Fermi liquid state in orbital two-channel Kondo effect(2CK). This anomalous resistivity upturn in Co$_{0.28}$TaS$_2$ can be attributed to the orbital two-channel Kondo mechanism.

cond-mat.str-el↗

arXiv2019

Anisotropic magnetic properties of trigonal ErAl$_2$Ge$_2$ single crystal

We report the anisotropic magnetic properties of the ternary compound ErAl$_2$Ge$_2$. Single crystals of this compound were grown by high temperature solution growth technique,using Al:Ge eutectic composition as flux. From the powder x-ray diffraction we confirmed that ErAl$_2$Ge$_2$ crystallizes in the trigonal CaAl$_2$Si$_2$-type crystal structure. The anisotropic magnetic properties of a single crystal were investigated by measuring the magnetic susceptibility, magnetization, heat capacity and electrical resistivity. A bulk magnetic ordering occurs around 4 K inferred from the magnetic susceptibility and the heat capacity. The magnetization measured along the $ab$-plane increases more rapidly than along the $c$-axis suggesting the basal $ab$-plane as the easy plane of magnetization. The magnetic susceptibility, magnetization and the $4f$-derived part of the heat capacity in the paramagnetic regime analysed based on the point charge model of the crystalline electric field (CEF) indicate a relatively low CEF energy level splitting.

cond-mat.str-el↗