RIJU PAL

@bose.res.in

Senior Research Fellow, Department of Condensed Matter & Materials Physics
S. N. Bose National Centre for Basic Sciences

RIJU PAL


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https://researchid.co/rijupal

RESEARCH, TEACHING, or OTHER INTERESTS

Condensed Matter Physics, Physics and Astronomy, Materials Science
11

Scopus Publications

126

Scholar Citations

7

Scholar h-index

5

Scholar i10-index

Scopus Publications

  • Observation of superconductivity and weak ferromagnetism in the quasi-one-dimensional chain compound (TaSe4)3I at ambient pressure
    Arnab Bera, Riju Pal, Buddhadeb Pal, Samir Rom, Suchanda Mondal, Deepti Rana, Aastha Vasdev, Sandeep Howlader, Manish Jana, Tanmay Maiti, Rafikul Ali Saha, Biswajit Das, Tanusri Saha-Dasgupta, Prabhat Mandal, Atindra Nath Pal, Mintu Mondal
    Physical Review B, 2025
    Quasi-one-dimensional (quasi-1D) materials, with electron motion confined to linear chains, form an attractive set of compounds to study the physical properties in low dimensions. In this work, we report the observation of superconductivity and weak ferromagnetism in the noncentrosymmetric phase of the quasi-1D ${({\mathrm{TaSe}}_{4})}_{3}\mathrm{I}$ single crystal. The superconductivity is probed by both the resistive transition and the Meissner effect below 2.5 K, while the ferromagnetic transition appears at $\ensuremath{\sim}9$ K. Furthermore, the current-voltage data exhibit phase slip events, a typical characteristic of low-dimensional superconductors. Although a definite mechanism is difficult to pinpoint, first-principles calculations-based theoretical study suggests that Se dimer vacancies may give rise to this unusual ground state, simultaneously hosting these two antagonistic quantum phases. The present results provide a platform to study complex ground states of such quasi-1D materials.
  • Ferromagnetic Resonance Spectroscopy on the Kagome Magnet MgMn6Sn6
    Riju Pal, Kakan Deb, Nitesh Kumar, Bernd Büchner, Alexey Alfonsov, Vladislav Kataev
    Applied Magnetic Resonance, 2025
    MgMn $$_{6}$$ 6 Sn $$_{6}$$ 6 is the itinerant ferromagnet on the kagome lattice with high ordering temperature featuring complex electronic properties due to the nontrivial topological electronic band structure where the spin–orbit coupling (SOC) plays a crucial role. Here, we report a detailed ferromagnetic resonance (FMR) spectroscopic study of MgMn $$_{6}$$ 6 Sn $$_{6}$$ 6 aimed to elucidate and quantify the intrinsic magnetocrystalline anisotropy that is responsible for the alignment of the Mn magnetic moments in the kagome plane. By analyzing the frequency, magnetic field, and temperature dependences of the FMR modes, we have quantified the magnetocrystalline anisotropy energy density that reaches the value of approximately $$3.5\\cdot 10^{6}$$ 3.5 · 10 6 erg/cm $$^{3}$$ 3 at $$T = 3$$ T = 3 K and reduces to about $$1\\cdot 10^{6}$$ 1 · 10 6 erg/cm $$^{3}$$ 3 at $$T = 300$$ T = 300 K. The revealed significantly strong magnetic anisotropy suggests a sizable contribution of the orbital magnetic moment to the spin magnetic moment of Mn, supporting the scenario of the essential role of SOC for the nontrivial electronic properties of MgMn $$_{6}$$ 6 Sn $$_{6}$$ 6 .
  • Spin-reorientation driven emergent phases and unconventional magnetotransport in quasi-2D vdW ferromagnet Fe4GeTe2
    Riju Pal, Buddhadeb Pal, Suchanda Mondal, Rajesh O. Sharma, Tanmoy Das, Prabhat Mandal, Atindra Nath Pal
    Npj 2d Materials and Applications, 2024
    Non-trivial spin textures driven by strong exchange interaction, magneto-crystalline anisotropy, and electron correlation in a low-dimensional magnetic material often lead to unusual electronic transitions. Through a combination of transport experiments in exfoliated nanoflakes down to 16 layers and first principle calculations, we unravel emergent electronic phases in quasi-2D van der Waals ferromagnet, Fe4GeTe2, possessing ferromagnetic TC ~ 270 K, along with a spin-reorientation transition (TSR ~ 120 K) with the change of magnetic easy axis. Two electronic transitions are identified. The first transition near TSR exhibits a sharp fall in resistivity, followed by a sign change in the ordinary Hall coefficient (R0), together with, maximum negative magnetoresistance (MR) and anomalous Hall conductivity. Another unusual electronic transition, hitherto unknown, is observed near ~ 40–50 K (TQ), where R0 again changes sign and below which, the resistivity shows a quadratic temperature dependence, and MR becomes positive. An analysis of the experimental data further uncovers the role of competing inelastic scattering processes in anomalous magnetotransport behavior. The density-functional theory based first-principle calculations unveil two possible magnetic phases, followed by a low-energy model Hamiltonian which captures the essence of these phases as well as explains the observed magnetotransport behavior. Thus, we demonstrate an interplay between magnetism and band topology and its consequence on electron transport in Fe4GeTe2, important for spintronic applications.
  • Disentangling the Unusual Magnetic Anisotropy of the Near-Room-Temperature Ferromagnet Fe4GeTe2
    Riju Pal, Joyal John Abraham, Alexander Mistonov, Swarnamayee Mishra, Nina Stilkerich, Suchanda Mondal, Prabhat Mandal, Atindra Nath Pal, Jochen Geck, Bernd Büchner, Vladislav Kataev, Alexey Alfonsov
    Advanced Functional Materials, 2024
    In the quest for 2D conducting materials with high ferromagnetic ordering temperature the new family of the layered FenGeTe2 compounds, especially the near‐room‐temperature ferromagnet Fe4GeTe2, receives a significant attention. Fe4GeTe2 features a peculiar spin reorientation transition at TSR ≈ 110 K suggesting a non‐trivial temperature evolution of the magnetic anisotropy (MA)—one of the main contributors to the stabilization of the magnetic order in the low‐dimensional systems. An electron spin resonance (ESR) spectroscopic study reported here provides quantitative insights into the unusual magnetic anisotropy of Fe4GeTe2. At high temperatures the total MA is mostly given by the demagnetization effect with a small contribution of the counteracting intrinsic magnetic anisotropy of an easy‐axis type, whose growth below a characteristic temperature Tshape ≈ 150 K renders the sample seemingly isotropic at TSR. Below one further temperature Td ≈ 50 K the intrinsic MA becomes even more complex. Importantly, all the characteristic temperatures found in the ESR experiment match those observed in transport measurements, suggesting an inherent coupling between magnetic and electronic degrees of freedom in Fe4GeTe2. This finding together with the observed signatures of the intrinsic two‐dimensionality should facilitate optimization routes for the use of Fe4GeTe2 in the magneto‐electronic devices, potentially even in the monolayer limit.
  • Intrinsic room temperature ferromagnetism in van der Waals Fe5GeTe2crystal
    Riju Pal, Satyabrata Bera, Buddhadeb Pal, Mintu Mondal, Atindra Nath Pal
    Aip Conference Proceedings, 2024
    Two dimensional magnetic materials have drawn a great attention in 2D magnetism and opened up a new direction for modern spintronic applications. Here, we have synthesized a cleavable Fe5GeTe2 material, which shows an intrinsic ferromagnetic behaviour at room temperature (∼310K). We have investigated the electronic and magnetic properties of the bulk Fe5GeTe2 single crystal. Our study reveals that bulk Fe5GeTe2 is metallic and behaves like an easy-axis ferromagnet along c-axis with a stronger in-plane magnetic anisotropy compared to the out of plane. However, the magnetic state of Fe5GeTe2 is much complex and still unclear, hence systematic investigation may lead this material as an ideal candidate for spintronic applications.
  • Space-charge driven origin of the reversible pyrocurrent peaks in Cu1-xCdxCr2 O4
    Abhishek Das, Riju Pal, Sakshi Mehta, Kazi Parvez Islam, Abhishake Mondal, Atindra Nath Pal, Debraj Choudhury
    Physical Review B, 2024
    ${\mathrm{CuCr}}_{2}{\mathrm{O}}_{4}$, which belongs to the family of ${AB}_{2}{\mathrm{O}}_{4}$ spinels, was recently reported to be a type-I multiferroic material. The observations of type-I multiferroicity, i.e., where ferroelectricity (FE) arises from a structural origin, is rare in the ${AB}_{2}{\mathrm{O}}_{4}$ spinel family, thus this result is significant. The role of both Jahn-Teller (JT) active ${\mathrm{Cu}}^{2+}$ and Cr sublattice magnetic ordering was suggested in the earlier study, and a more careful investigation to elucidate the origin of the observed FE is required. With the aim to elucidate the origin of the observed FE, we carried out a detailed investigation of the structural, electrical, and magnetic properties of a ${\mathrm{Cu}}_{1\ensuremath{-}x}{\mathrm{Cd}}_{x}{\mathrm{Cr}}_{2}{\mathrm{O}}_{4}$ $(0\ensuremath{\le}x\ensuremath{\le}1)$ series, that enables an $x$-dependent controlled tuning of the ${\mathrm{Cu}}^{2+}$ driven structural and Cr-sublattice driven magnetic transition temperatures. We track and investigate the correlation of the observed pyrocurrent peaks with the temperature-dependent structural and magnetic transitions in this series for various $x$ members. From careful investigations, we rule out any intrinsic origin and establish a space-charge or extrinsic origin for the observed switchable pyrocurrent peaks that point to an absence of ferroelectricity.
  • Detection of Nontrivial Topology Driven by Charge Density Wave in a Semi-Dirac Metal
    Rafiqul Alam, Prasun Boyal, Shubhankar Roy, Ratnadwip Singha, Buddhadeb Pal, Riju Pal, Prabhat Mandal, Priya Mahadevan, Atindra Nath Pal
    Advanced Functional Materials, 2023
    The presence of electron correlations in a system with topological order can lead to exotic ground states. Considering single crystals of LaAgSb2 which has a square net crystal structure, one finds multiple charge density wave transitions (CDW) as the temperature is lowered. Large planar Hall (PHE) signals are found in the CDW phase, which are still finite in the high‐temperature phase though they change sign. Optimizing the structure within first‐principles calculations, one finds an unusual chiral metallic phase. This is because as the temperature is lowered, the separation between the Ag/Sb atoms on different layers decreases, leading to stronger repulsions between electrons associated with atoms on different layers. This leads to successive layers sliding with respect to each other, thereby stabilizing a chiral structure in which inversion symmetry is also broken. The large Berry curvature associated with the low‐temperature structure explains the low‐temperature PHE. At high temperature, the PHE arises from the changes induced in the anisotropic Dirac cone in presence of a magnetic field. This work represents a route toward detecting and understanding the mechanism in a correlation‐driven topological transition through electron transport measurements, complemented by ab‐initio electronic structure calculations.
  • Enhanced coercivity and emergent spin-cluster-glass state in 2D ferromagnetic material, Fe3GeTe2
    Satyabrata Bera, Suman Kalyan Pradhan, Riju Pal, Buddhadeb Pal, Arnab Bera, Sk Kalimuddin, Manjil Das, Deep Singha Roy, Hasan Afzal, Atindra Nath Pal, Mintu Mondal
    Journal of Magnetism and Magnetic Materials, 2023
  • Tuning of magnetic frustration and emergence of a magnetostructural transition in Mn1-xCdxCr2 O4
    Abhishek Das, Dheeraj Ranaut, Pratap Pal, Riju Pal, Shubhadip Moulick, Moumita Das, Dinesh Topwal, Prabhat Mandal, Atindra Nath Pal, K. Mukherjee, Debraj Choudhury
    Physical Review B, 2023
    ${\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Cd}}_{x}{\mathrm{Cr}}_{2}{\mathrm{O}}_{4}$ spinel series is engineered to host a controlled and wide-range tuning of magnetic frustration through a nonmagnetic ion (Cd) doping in ${\mathrm{MnCr}}_{2}{\mathrm{O}}_{4}$ spinel oxide. While ${\mathrm{MnCr}}_{2}{\mathrm{O}}_{4}$ exhibits weak geometric magnetic frustration (GMF), the doping brings in an interplay between various competing magnetic-exchange interactions involving the Jahn-Teller inactive ${\mathrm{Cr}}^{3+}$($3d{}^{3}$) spins that lie on a frustrated pyrochlore lattice in cubic spinel oxide. Magnetic frustration is observed to be the maximum for the intermediate values of $\mathit{x}$ which are associated with large spin-relaxation times and an evolution in the nature of glassy spin dynamics. The dominant antiferromagnetic coupling between the Mn sites and Cr sites (which induces the intra-Cr-lattice spins to be nearly ferromagnetically coupled in $x=0)$ becomes weaker due to magnetic dilution of the Mn site by diamagnetic ${\mathrm{Cd}}^{2+}$ ions. As a result, the net interactions between ${\mathrm{Cr}}^{3+}$ ions in the pyrochlore lattice become antiferromagnetic beyond $x\ensuremath{\gtrsim}0.6$. This causes the associated GMF to become very large for $x\ensuremath{\gtrsim}0.6$. As a result, while the structure remains cubic till the lowest temperature for $0\ensuremath{\le}x\ensuremath{\le}0.60$, the appearance of strong GMF induces spin-driven magnetostructural transitions from a high-temperature cubic (paramagnetic) to a low-temperature tetragonal (and antiferromagnetic) phase. The obtained results demonstrate a direct link between GMF and spin-lattice coupling and provide a road map to design compounds with engineered magnetostructural transitions associated with large spin-lattice coupling.
  • Surface-phase superconductivity in a Mg-deficient V-doped MgTi2 O4 spinel
    A. Rahaman, T. Paramanik, B. Pal, R. Pal, P. Maji, K. Bera, S. Mallik, D. K. Goswami, A. N. Pal, D. Choudhury
    Physical Review B, 2023
    Around 50 years ago, ${\mathrm{LiTi}}_{2}{\mathrm{O}}_{4}$ was reported to be the only spinel oxide to exhibit a superconducting transition with the highest ${T}_{c}\ensuremath{\approx}13.7$ K. Recently, ${\mathrm{MgTi}}_{2}{\mathrm{O}}_{4}$ has been found to be another spinel oxide to reveal a superconducting transition with ${T}_{c}\ensuremath{\approx}3$ K, however, its superconducting state is realized only in thin film superlattices involving ${\mathrm{SrTiO}}_{3}$. We find that a V-doped ${\mathrm{Mg}}_{1\ensuremath{-}x}{\mathrm{Ti}}_{2}{\mathrm{O}}_{4}$ phase, which gets stabilized as a thin surface layer on top of a nearly stoichiometric and insulating V-doped ${\mathrm{MgTi}}_{2}{\mathrm{O}}_{4}$ bulk sample, exhibits high-temperature superconductivity with ${T}_{c}\ensuremath{\approx}16$ K. The superconducting transition is also confirmed through a concomitant sharp diamagnetic transition immediately below ${T}_{c}$. The spinel phase of the superconducting surface layer is conformed through grazing-incidence x-ray diffraction and micro-Raman spectroscopy. A small shift of the sharp superconducting transition temperature ($\ensuremath{\sim}4$ K) with the application of a high magnetic field (up to 9 T) suggests a very high critical field for the system, $\ensuremath{\sim}25$ T. Thus, V-doped ${\mathrm{Mg}}_{1\ensuremath{-}x}{\mathrm{Ti}}_{2}{\mathrm{O}}_{4}$ exhibits the maximum ${T}_{c}$ among spinel superconductors and also possesses a very high critical field.
  • Unravelling the nature of spin reorientation transition in quasi-2D vdW magnetic material, Fe4GeTe2
    Satyabrata Bera, Suman Kalyan Pradhan, Md Salman Khan, Riju Pal, Buddhadeb Pal, Sk Kalimuddin, Arnab Bera, Biswajit Das, Atindra Nath Pal, Mintu Mondal
    Journal of Magnetism and Magnetic Materials, 2023

RECENT SCHOLAR PUBLICATIONS

  • Skyrmionic transport and first-order phase transitions in a twisted bilayer graphene quantum Hall ferromagnet
    V Pandey, P Ghosh, R Pal, S Paul, AM B, K Watanabe, T Taniguchi, ...
    Physical Review B (Letter) 113 (16), L161110 , 2026
    2026
  • Spin Reorientation Driven Renormalization of Spin-Phonon Coupling in Fe GeTe
    R Pal, MN Hasan, C Nayak, M Deka, N Salehi, M Pereiro, S Mondal, ...
    arXiv preprint arXiv:2512.18544 , 2025
    2025
  • Transport and Spectroscopic Studies of Layered Magnetic and Low Dimensional Superconducting Materials
    R Pal
    https://share.google/O0ihc0CMS6r99c6hb , 2025
    2025
  • Observation of superconductivity and weak ferromagnetism in the quasi-one-dimensional chain compound (TaSe ) I at ambient pressure
    A Bera, R Pal, B Pal, S Rom, S Mondal, D Rana, A Vasdev, S Howlader, ...
    Physical Review B (Letter) 112 (18), L180502 , 2025
    2025
    Citations: 10
  • Ferromagnetic Resonance Spectroscopy on the Kagome Magnet MgMn Sn
    R Pal*, K Deb, N Kumar, B Büchner, A Alfonsov, V Kataev*
    Applied Magnetic Resonance 56 (11), 1507-1521 , 2025
    2025
    Citations: 3
  • Disentangling the Unusual Magnetic Anisotropy of the Near‐Room‐Temperature Ferromagnet Fe GeTe
    R Pal, JJ Abraham, A Mistonov, S Mishra, N Stilkerich, S Mondal, ...
    Advanced Functional Materials 34 (38), 2402551 , 2024
    2024
    Citations: 17
  • Spin-reorientation driven emergent phases and unconventional magnetotransport in quasi-2D vdW ferromagnet Fe 4 GeTe 2
    R Pal, B Pal, S Mondal, RO Sharma, T Das, P Mandal, AN Pal
    npj 2D Materials and Applications 8 (1), 30 , 2024
    2024
    Citations: 28
  • Intrinsic room temperature ferromagnetism in van der Waals Fe GeTe crystal
    R Pal, S Bera, B Pal, M Mondal, AN Pal
    AIP Conference Proceedings 3067 (1) , 2024
    2024
    Citations: 2
  • Space-charge driven origin of the reversible pyrocurrent peaks in
    A Das, R Pal, S Mehta, KP Islam, A Mondal, AN Pal, D Choudhury
    Physical Review B 109 (2), 024104 , 2024
    2024
    Citations: 4
  • Enhanced coercivity and emergent spin-cluster-glass state in 2D ferromagnetic material, Fe GeTe
    S Bera, SK Pradhan, R Pal, B Pal, A Bera, S Kalimuddin, M Das, DS Roy, ...
    Journal of Magnetism and Magnetic Materials 583, 171052 , 2023
    2023
    Citations: 9
  • Detection of Nontrivial Topology Driven by Charge Density Wave in a Semi‐Dirac Metal
    R Alam, P Boyal, S Roy, R Singha, B Pal, R Pal, P Mandal, P Mahadevan, ...
    Advanced Functional Materials 33 (44), 2306751 , 2023
    2023
    Citations: 3
  • Tuning of magnetic frustration and emergence of a magnetostructural transition in
    A Das, D Ranaut, P Pal, R Pal, S Moulick, M Das, D Topwal, P Mandal, ...
    Physical Review B 108 (6), 064426 , 2023
    2023
    Citations: 10
  • Surface-phase superconductivity in a Mg-deficient V-doped spinel
    A Rahaman, T Paramanik, B Pal, R Pal, P Maji, K Bera, S Mallik, ...
    Physical Review B 107 (24), 245124 , 2023
    2023
    Citations: 7
  • Unravelling the nature of spin reorientation transition in quasi-2D vdW magnetic material, Fe GeTe
    S Bera, SK Pradhan, MS Khan, R Pal, B Pal, S Kalimuddin, A Bera, B Das, ...
    Journal of Magnetism and Magnetic Materials 565, 170257 , 2023
    2023
    Citations: 33

MOST CITED SCHOLAR PUBLICATIONS

  • Unravelling the nature of spin reorientation transition in quasi-2D vdW magnetic material, Fe GeTe
    S Bera, SK Pradhan, MS Khan, R Pal, B Pal, S Kalimuddin, A Bera, B Das, ...
    Journal of Magnetism and Magnetic Materials 565, 170257 , 2023
    2023
    Citations: 33
  • Spin-reorientation driven emergent phases and unconventional magnetotransport in quasi-2D vdW ferromagnet Fe 4 GeTe 2
    R Pal, B Pal, S Mondal, RO Sharma, T Das, P Mandal, AN Pal
    npj 2D Materials and Applications 8 (1), 30 , 2024
    2024
    Citations: 28
  • Disentangling the Unusual Magnetic Anisotropy of the Near‐Room‐Temperature Ferromagnet Fe GeTe
    R Pal, JJ Abraham, A Mistonov, S Mishra, N Stilkerich, S Mondal, ...
    Advanced Functional Materials 34 (38), 2402551 , 2024
    2024
    Citations: 17
  • Observation of superconductivity and weak ferromagnetism in the quasi-one-dimensional chain compound (TaSe ) I at ambient pressure
    A Bera, R Pal, B Pal, S Rom, S Mondal, D Rana, A Vasdev, S Howlader, ...
    Physical Review B (Letter) 112 (18), L180502 , 2025
    2025
    Citations: 10
  • Tuning of magnetic frustration and emergence of a magnetostructural transition in
    A Das, D Ranaut, P Pal, R Pal, S Moulick, M Das, D Topwal, P Mandal, ...
    Physical Review B 108 (6), 064426 , 2023
    2023
    Citations: 10
  • Enhanced coercivity and emergent spin-cluster-glass state in 2D ferromagnetic material, Fe GeTe
    S Bera, SK Pradhan, R Pal, B Pal, A Bera, S Kalimuddin, M Das, DS Roy, ...
    Journal of Magnetism and Magnetic Materials 583, 171052 , 2023
    2023
    Citations: 9
  • Surface-phase superconductivity in a Mg-deficient V-doped spinel
    A Rahaman, T Paramanik, B Pal, R Pal, P Maji, K Bera, S Mallik, ...
    Physical Review B 107 (24), 245124 , 2023
    2023
    Citations: 7
  • Space-charge driven origin of the reversible pyrocurrent peaks in
    A Das, R Pal, S Mehta, KP Islam, A Mondal, AN Pal, D Choudhury
    Physical Review B 109 (2), 024104 , 2024
    2024
    Citations: 4
  • Ferromagnetic Resonance Spectroscopy on the Kagome Magnet MgMn Sn
    R Pal*, K Deb, N Kumar, B Büchner, A Alfonsov, V Kataev*
    Applied Magnetic Resonance 56 (11), 1507-1521 , 2025
    2025
    Citations: 3
  • Detection of Nontrivial Topology Driven by Charge Density Wave in a Semi‐Dirac Metal
    R Alam, P Boyal, S Roy, R Singha, B Pal, R Pal, P Mandal, P Mahadevan, ...
    Advanced Functional Materials 33 (44), 2306751 , 2023
    2023
    Citations: 3
  • Intrinsic room temperature ferromagnetism in van der Waals Fe GeTe crystal
    R Pal, S Bera, B Pal, M Mondal, AN Pal
    AIP Conference Proceedings 3067 (1) , 2024
    2024
    Citations: 2
  • Skyrmionic transport and first-order phase transitions in a twisted bilayer graphene quantum Hall ferromagnet
    V Pandey, P Ghosh, R Pal, S Paul, AM B, K Watanabe, T Taniguchi, ...
    Physical Review B (Letter) 113 (16), L161110 , 2026
    2026
  • Spin Reorientation Driven Renormalization of Spin-Phonon Coupling in Fe GeTe
    R Pal, MN Hasan, C Nayak, M Deka, N Salehi, M Pereiro, S Mondal, ...
    arXiv preprint arXiv:2512.18544 , 2025
    2025
  • Transport and Spectroscopic Studies of Layered Magnetic and Low Dimensional Superconducting Materials
    R Pal
    https://share.google/O0ihc0CMS6r99c6hb , 2025
    2025

Publications

Pal, R., Pal, B., Mondal, S. et al. Spin-reorientation driven emergent phases and unconventional magnetotransport in quasi-2D vdW ferromagnet Fe4GeTe2. npj 2D Mater Appl 8, 30 (2024).

R. Pal, J. J. Abraham, A. Mistonov, et al. Disentangling the Unusual Magnetic Anisotropy of the Near‐Room‐Temperature Ferromagnet Fe4GeTe2. Advanced Functional Materials, 2402551 (2024).