arXiv subjects

B. Maji

Publications and source records attributed to B. Maji.

4 recordsLinked to original sources

arXiv2024

Effect of nonmagnetic Ti substitution on the structural, magnetic and transport properties in pyrochlore iridate Eu2(Ir1-xTix)2O7

We have studied the effect of nonmagnetic Ti substitution Eu2(Ir1-xTix)2O7 with the help of electrical transport and magnetic measurement. The minor structural modification enhances the orbital overlapping and favours its electrical transport properties with Ti doping though the tuning of SOC and U with site dilution opposes it. As a result, metal insulator transition (MIT) is disappeared and resistivity of the system throughout the temperature increases with Ti doping. The nature of the conduction mechanism at low temperature follows power law like variation. As the Ti4+ is nonmagnetic, the introduction of Ti at Ir site dilutes the magnetic interaction at Ir octahedral network, which in turn decreases the magnetic moment and magnetic frustration in the system though the magnetic irreversibility temperature is hardly affected by Ti.

cond-mat.str-el↗

arXiv2022

Evolution of magnetic and transport properties in Cu doped pyrochlore iridate Eu2(Ir1-xCux)2O7

We have investigated the effect of Cu substitution in Eu2(Ir1-xCux)2O7 with the help of magnetic and transport property measurements. XPS measurement reveals that each Cu2+ converts Ir4+ to double amount of Ir5+ ions. The metal-insulator transition temperature (T_MI) is obtained around 120 K. In the insulating phase, at lower temperature below 50 K, the temperature dependent resistivity follows a power law dependence and the magnitude of the exponent increases with Cu concentrations. The temperature dependent thermopower is observed to follow the electrical resistivity down to 50 K, except for a sudden drop in thermopower at temperature below 50 K. We find negligible Hall voltage in the metallic regime of the samples but a sudden Hall voltage is developed below 50 K. We observe bifurcation in zero field cooled and field cooled (ZFC-FC) magnetization below irreversibility temperature, exchange bias and negative magnetoresistance at 3 K and the magnitude of all these properties increases with Cu concentrations. In the insulating region (below 6 K) there exists a linear specific heat and its coefficient decreases with Cu doping which indicates the reduction of spinon contribution with Cu doping.

cond-mat.str-el↗

arXiv2020

Role of f-d exchange interaction and Kondo scattering in Nd doped pyrochlore Iridate (Eu1-xNdx)2Ir2O7

We report study of magnetization, resistivity, magnetoresistance and specific heat of the pyrochlore Iridate (Eu1-xNdx)2Ir2O7 with x=0.0, 0.5 and 1.0, where spin orbit coupling, electronic correlation, magnetic frustration and Kondo scattering coexists. Metal insulator transition temperature (T_MI) decrease with increase in Nd content but always coincides with magnetic irreversibility temperature (field induced moment). Resistivity below T_MI do not fit with either activated (gap) or to any power law (gapless) dependence. The Curie constant show surprising result, that Nd induces singlet correlation (reduction of para-moment) in Ir sublattice. Magnetoresistance is negative at low temperatures below 10 K and increases strongly with increase in x and vary quadratically with field switching over to linear dependence above 50 kOe. Low temperature specific heat shows Schottky peak, coming from Nd moments, showing existence of doublet split in Nd energy level, arising from f-d exchange interaction. All materials show presence of a linear specific heat in the insulating region. The coefficient of linear specific heat for x= 0.0 does not vary with external magnetic field but varies superlinearly for x = 1.0 materials. We argue that linear specific heat probably rules out weakly correlated phases like Weyl fermions. We propose that with the introduction of Nd at Eu site the system evolves from chiral spin liquid with gapless spinon excitations with a very small charge gap to Kondo type interaction superposed on chiral spin liquid coexisting with long range antiferromagnetic ordering. Huge increase of magnetoresistance with increase in Nd concentrations shows importance of Kondo scattering in the chiral spin liquid material by rare earth moments.

cond-mat.str-el↗

arXiv2017

Perfect powers in alternating sum of consecutive cubes

In this paper, we consider the problem about finding out perfect powers in an alternating sum of consecutive cubes. More precisely, we completely solve the Diophantine equation $(x+1)^3 - (x+2)^3 + \cdots - (x + 2d)^3 + (x + 2d + 1)^3 = z^p$, where $p$ is prime and $x,d,z$ are integers with $1 \leq d \leq 50$.

math.NT↗