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Abstract Band structure tailoring has been a great avenue to achieve the half-metallic electronic ground state in materials. Applying this approach to the full Heusler alloy Fe2TiSn, Cr is introduced systematically at Ti site that conforms to the chemical formula $${\text{Fe}}_{2} {\text{Ti}}_{{1 - x}} {\text{Cr}}_{x}$$ Fe 2 Ti 1 - x Cr x Sn. Compositions so obtained have been investigated for its electronic, magnetic, and electrical transport properties with an aim to observe the half-metallic ferromagnetic ground state, anticipated theoretically for Fe2CrSn. Our experimental study using synchrotron X-ray diffraction reveals that only compositions with $$x \le$$ x ≤ 0.25 yield phase pure L2 $$_1$$ 1 cubic structures. The non-magnetic ground state of Fe2TiSn gets dramatically affected upon inclusion of Cr giving rise to a localized magnetic moment in the background of Ruderman–Kittel–Kasuya–Yosida (RKKY) correlations. The ferromagnetic interactions begin to dominate for x = 0.25 composition. Results of its resistivity and magnetoresistance (MR) measurement point towards a half-metallic ground state. The calculation of exchange coupling parameter, $$\hbox {J}_{{ij}}$$ J ij , and orbital projected density of states that indicate a change in hybridization between 3d and 5p orbital, support the observations made from the study of local crystal structure made using the extended X-ray absorption fine structure spectroscopy. Our findings here highlight an interesting prospect of finding half-metallicity via band structure tailoring for wide application in spintronics devices.

Introduction: Both terbinafine and fluconazole are effective systemic drugs for dermatophytosis. They can be used intermittently as pulse doses or as daily doses for the treatment of the same. Aim: The aim of this study was to assess the efficacy and safety of 1 week twice a day therapy of terbinafine and to compare it with that of a daily 2-week course of terbinafine and weekly pulse fluconazole therapy. The adverse effects and relapse rates after the completion of therapy were assessed. Materials and Methods: A study was conducted with 90 patients divided into three Groups A, B, and C. Patients were assessed at 2 and 4 weeks of starting treatment and 6 weeks following the completion of treatment. Adverse effects if any were noted. Clinical scores were calculated, and skin scraping for potassium hydroxide (KOH) examination was done. Clinical improvement was assessed. A mycological cure is defined as a negative KOH examination. Results: There was a significant decrease in clinical scores before treatment and at 2 and 4 weeks of visits. The highest clinical cure rates were attained in Group A (80%), followed by Group B (73.33%) and Group C (63.3%). Mycological cure rate at 4 weeks was highest in Group A (93.3%), followed by Group B (86.7%) and Group C (83.3%). This difference in clinical and mycological cure rates in the three groups was not found to be statistically significant. Of the patients who had responded to treatment at 4 weeks, the clinical and mycological cure was maintained in 96.4% individuals in Group A, 96.1% in Group B, and 88% in Group C at 6 weeks. Thus, the highest number of recurrences was seen in Group C, followed by Group B and Group A. All the three treatment regimens were well tolerated. Side effects were seen in 17 patients. They were mild and predominantly gastrointestinal. Conclusion: All three drugs in different regimens were found to be equally efficacious in the treatment of dermatophytic infections in our center.

Pyoderma gangrenosum (PG) is rare in children. We report a case of PG in a 4-year-old male who presented with ulcers over face, axillae, and gluteal area. The ulcers healed with cribriform scarring after starting systemic steroids and azathioprine. The patient, however, was unable to follow-up regularly. He had a recurrence of lesions developed sepsis and septic shock and unfortunately expired.

Occurence of psoriasis and leprosy in a single patient is extremely rare with very few cases reported. Better knowledge of the pathogenesis of these two diseases has led to some understanding of this rare association. We report such an association in one of our patients. We also report the therapeutic dilemma faced in treating lepra reaction with steroids while preventing the acute flare-up of psoriasis.

Pseudolymphomas are a group of disorders, which clinically and histopathologically mimic lymphomas. A 38-year-old female presented with a plaque over the forehead. A biopsy revealed a nodular infiltrate of lymphocytes that was suggestive of pseudolymphoma. The lesion spontaneously regressed over 9 days of biopsy, leaving behind hyperpigmentation.

Keratoelastoidosis marginalis of the hands (KEMH) is a distinct solar elastotic dermatosis belonging to the group of marginal keratoderma. It is characterized by linear plaques on the hand and calcified dermal elastotic masses predominantly affecting the radial side of the index finger, first web space, and ulnar side of the thumb. It is predominantly seen in the middle-aged and elderly age group. We report the occurrence of KEMH in two farmers with other cutaneous features of chronic actinic damage.

Giant-cell tumor of the tendon sheath (GCTTS) is a benign soft tissue tumor of the limbs arising from the complex of the tendon sheath and periarticular soft tissues of small joints. It is the second most common benign space occupying lesion in the hand and usually presents as a painless soft tissue mass, which grows slowly in size for many years. We present an interesting case of an enormous GCTTS presenting as a slowly growing mass over left sole of a 52-year-old woman. The duration of GCTTS may range from a few weeks to 30 years but in our case the duration of tumor was almost 48 years, which could be the longest reported duration of GCTTS.

A nonmagnetic full Heusler alloy, Fe 2 TiSn , was substituted with Si, Ge, and Sb at the Sn site with a primary aim of investigating the physical properties of these compositions that are much anticipated to result in a high thermoelectric power factor and generate a half-metallic ground state. The X-ray diffraction (XRD) study carried out using the synchrotron source confirms the solubility limit of substituent atoms to be a mere 5% for Si and Ge and 60% for Sb that results in a pure L 2 1 Heusler phase. Rietveld refinement of the XRD profiles yields the lattice parameters. Despite the fact that chemical substitution should lead to atomic disorder and an increase in the scattering of charge carriers, resistivity measurements show a significant decrease in the magnitude with as little as 5% substitution of Sn by Si or Ge. The weak localization present in Fe 2 TiSn seems to drastically reduce in the substituted compositions, and the long range magnetic order seems to affect the transport of the charge carriers. The origin of magnetic interactions is investigated using extended X-ray absorption fine structure spectroscopy. The changes in the local crystal structure in terms of the Fe–Fe bond distance are determined. The inference drawn from the experimental study is further complemented with exchange coupling parameter, J ij , and orbital projected density of states calculations, thus presenting an overall understanding of the origin of magnetic interactions in these technologically relevant compositions. [ABSTRACT FROM AUTHOR]

A combination of high optical transparency and good electrical conductivity is realized in CuCrO2, a p-type transparent conducting oxide. With an aim to improve its physical properties, a CuCr1-xTixO2 (x=0, 0.05, 0.1) series was prepared and investigated for its structural, electrical transport, and optical properties. Along with the lattice parameter values, refinement of X-ray diffraction profiles confirm the solubility limit of Ti within the delafossite unit cell. Electrical resistivity and heat capacity measured by varying the temperature further characterize the Ti-substituted compositions. As determined from ultraviolet-visible spectroscopy, no significant changes take place in the optical gap of CuCrO2 with Ti addition. Apart from confirming the 4þvalence state of Ti, the X-ray absorption near edge structure highlights the subtle changes taking place in the Cu-O hybridization upon Ti-substitution. The analysis of temperature dependent extended X-ray absorption fine structure spectroscopy, recorded at the Cr and Cu K-edge, emphasizes the impact of redistribution of charges on the local crystal structure. Cu-Cu hybridization along the a-axis appears to be influenced mainly by the temperature and only slightly by Ti substitution. [ABSTRACT FROM AUTHOR]

The direct Cr-Cr and Cr-Se-Cr exchange interactions and the associated spin-phonon coupling are crucial for the much envisaged multiferroicity in CdCr2Se4 spinel chalcogenide. The static chemical disorder created by the Sn4+ substitution at the Cd2+ site in CdCr2Se4 affects the local crystal structure around Cr-ions, and hence its magnetism. Although the spinel structure is maintained, the trends in lattice parameters are not a linear function of increasing Sn concentration. The magnetic properties are patterned after the trend in lattice parameters but in the opposite direction. Hence, a detailed investigation into the changing local crystal structure of Cd1-xSnxCr2Se4 for (0 ≤ x ≤ 0.1) using EXAFS and XRD was carried out. Variation in the Cr-Se and Cr-Cr bonding is traced across the changing Sn-content. Raman spectroscopy probes the thermal excitations coupled with spin waves across the magnetic ordering temperature. The synchrotron x-ray diffraction results further complement the inference drawn from Raman studies. Our results highlight the significance of an intricate balance between spin and lattice degrees of freedom in controlling the magnetoelasticity and, hence, the spin-phonon coupling in CdCr2Se4. [ABSTRACT FROM AUTHOR]

Transition metal compounds often undergo spin-charge-orbital ordering due to strong electron-electron correlations. In contrast, low-dimensional materials can exhibit a Peierls transition arising from low-energy electron-phonon-coupling-induced structural instabilities. We study the electronic structure of the tunnel framework compound K_{2}Cr_{8}O_{16}, which exhibits a temperature-dependent (T-dependent) paramagnetic-to-ferromagnetic-metal transition at T_{C}=180 K and transforms into a ferromagnetic insulator below T_{MI}=95 K. We observe clear T-dependent dynamic valence (charge) fluctuations from above T_{C} to T_{MI}, which effectively get pinned to an average nominal valence of Cr^{+3.75} (Cr^{4+}∶Cr^{3+} states in a 3∶1 ratio) in the ferromagnetic-insulating phase. High-resolution laser photoemission shows a T-dependent BCS-type energy gap, with 2G(0)∼3.5(k_{B}T_{MI})∼35 meV. First-principles band-structure calculations, using the experimentally estimated on-site Coulomb energy of U∼4 eV, establish the necessity of strong correlations and finite structural distortions for driving the metal-insulator transition. In spite of the strong correlations, the nonintegral occupancy (2.25 d-electrons/Cr) and the half-metallic ferromagnetism in the t_{2g} up-spin band favor a low-energy Peierls metal-insulator transition.

Rowell′s syndrome is now identified as a subtype of subacute lupus erythematosus (LE) with erythema multiforme-like skin lesions, positive serum rheumatoid factor, anti-Ro La positivity and speckled pattern of antinuclear antibodies. Here we describe a case of Rowell′s syndrome in an 18-year-old female who was found to be ds-DNA negative, who later progressed to develop stage V lupus nephritis (LN) over a course of 4 months. Although extremely rare, most cases of LN are drug induced. Of only seven cases of non-drug induced LN with negative dsDNA, none had cutaneous involvement. Ours was a unique case of progression of Rowells syndrome to ds-DNA negative LN.

Interplay between structural disorder and magnetic interaction is investigated here for a multiferroic candidate material, CdCr2Se4. Ferromagnetic order in CdCr2Se4 sets in below TC~130K as a result of competition between the direct Cr-Cr spin coupling and the near neighbour Cr-Se-Cr exchange interactions. Hence, a small change in the crystal structure is expected to drastically affect its magnetic order. In this report, local lattice distortions within the overall cubic symmetry were brought about by replacing a small percentage of Se by isovalent S. Detailed crystal structure study using EXAFS and Raman Spectroscopy reflects the presence of local distortions within the overall cubic symmetry. Contrary to the expectation, magnetic properties of the substituted compositions do not show any drastic changes. Though, a signature of spin-phonon coupling is present across the magnetic ordering temperature. No structural phase transition occurs within the investigated temperature range of 80-300K. [ABSTRACT FROM AUTHOR]

Interplay between structural disorder and magnetic interaction is investigated here for a multiferroic candidate material, CdCr2Se4. Ferromagnetic order in CdCr2Se4 sets in below TC~130K as a result of competition between the direct Cr-Cr spin coupling and the near neighbour Cr-Se-Cr exchange interactions. Hence, a small change in the crystal structure is expected to drastically affect its magnetic order. In this report, local lattice distortions within the overall cubic symmetry were brought about by replacing a small percentage of Se by isovalent S. Detailed crystal structure study using EXAFS and Raman Spectroscopy reflects the presence of local distortions within the overall cubic symmetry. Contrary to the expectation, magnetic properties of the substituted compositions do not show any drastic changes. Though, a signature of spin-phonon coupling is present across the magnetic ordering temperature. No structural phase transition occurs within the investigated temperature range of 80-300K. [ABSTRACT FROM AUTHOR]

We have investigated the structure, transport and magnetic properties of Ni2MnSb0.5Al0.5 Heusler alloy. Structural analysis using x-ray diffraction and scanning electron microscopy has confirmed Ni2MnSb0.5Al0.5 to be a natural composite of Ni2MnSb and Ni2MnAl phases, regardless of annealing conditions. This composite has a dendritic microstructure formed by the phase separation during solidification. The electronic phase separation was confirmed using x-ray near edge absorption spectroscopy, recorded at Mn and Ni K-edge and supported by ab-initio calculations of the same using multiple scattering theory. A thorough characterization of this novel composite form of Ni2MnSb0.5Al0.5 Heusler alloy has been carried out by recording its magnetic and transport properties including electrical resistivity, thermal conductivity, and heat capacity. The composite micro-structure of this system plays a crucial role in drastically reducing its thermal conductivity value, while maintaining its metallic character. Unlike many oxide composites, the magnetic properties of the Ni2MnSb0.5Al0.5 cannot be considered as the volume average of the characteristics of the two phases, rather it shows a long range ferromagnetic order with Curie temperature of 334 K and magnetic moment of 2.52 /f.u. [ABSTRACT FROM AUTHOR]

The effect of Mo substitution at Ti site of orthorhombic Sm5Ge4-type R2Ti3Ge4 compounds on the magnetic and electrical transport properties has been studied. The Tb2Ti3-xMoxGe4 (x=0.3,0.75) and Er2Ti2.7Mo0.3Ge4 compounds have been synthesized and it is found that these compounds retain parent crystal structure at room temperature (space group Pnma, No. 62). Mo substitution decreases the antiferromagnetic ordering temperature (TN) of Tb2Ti3Ge4 compound from ∼18 to ∼13 and ∼10 K, respectively, for x=0.3 and 0.75. The Er2Ti2.7Mo0.3Ge4 compound shows a tendency to order at ∼2 K, whereas the parent Er2Ti3Ge4 is magnetically ordered at 3 K. Magnetization versus field data of Tb2Ti3-xMoxGe4 (x=0.3,0.75) reveal soft ferromagnetic nature. The metamagnetic transition that is present in parent Tb2Ti3Ge4 is found to disappear with Mo substitution. Magnetization value reaches ∼6.2μB/Tb3+ at 2 K in fields of 8 T, indicating incomplete ferromagnetic ordering with or without an antiferromagnetic component. Electrical resistivity of the Tb-based compounds has a linear variation with temperature from 300 to ∼50 K and shows a prominent slope change at temperatures much above TN, supporting the presence of competing short range ferromagnetic interactions. [ABSTRACT FROM AUTHOR]

With an intention of improving the figure of merit (ZT) of SnSe, we substitute up to 10% of Cu in place of Sn in SnSe. After confirming the phase purity, crystal structure, and stoichiometry of the prepared compositions using X-ray diffraction and energy dispersive spectroscopy, the microstructure was examined by field emission scanning electron microscopy. Thorough examination of the transport properties in the temperature range of 5–400 K was undertaken. In particular, four-probe electrical resistivity, Hall effect, Seebeck coefficient, and thermal conductivity were recorded for all compositions. Heat capacity was also measured. The results show peculiar nature of Sn1−xCuxSe; a small percentage of Cu addition acts as an annihilation center for the holes in SnSe. But as the substitution percentage is increased, the electrons contributed by the d-band of Cu seem to add a sizable concentration of charge carriers at the Fermi level which affects its transport properties. However, the p-type nature of conduction in SnSe does not change. Owing to the increased participation of electrons in the conduction process, a maximum carrier concentration of 1.12 × 1018 cm−3 (10% Cu-substitution) is observed. Thermopower can no longer be attributed to a single parabolic band structure for the Sn1−xCuxSe series. Interestingly, the thermal conductivity and heat capacity values remain nearly unchanged. With an improvement in the value of ZT (1.02 at 300 K) and compatibility factor of ≤2, we find that replacing a small percentage of Sn with Cu can be a good alternative to improve the performance of polycrystalline SnSe. [ABSTRACT FROM AUTHOR]

Magnetism in Ni-Mn-Z (Z=Ga, In, Sn, Sb) Heusler alloys has so far been predominantly attributed to Rudermann-Kittel-Kasuya-Yoshida type interactions between Mn atoms. We investigate magnetic interactions in one such alloy, Ni2Mn1.4In0.6, and attempt to explain the origin of antiferromagnetic (AFM) interactions that coexist with ferromagnetic ones. Through the combination of x-ray absorption spectroscopy and x-ray magnetic circular dichroism (XMCD), we find that Ni plays an important role along with Mn in the overall magnetism. A significant hybridization that develops between Mn and Ni orbitals results in a small antiferromagnetic moment at Ni sites. The shift in the XMCD hysteresis loops in the martensitic phase suggests that antiferromagnetism results from superexchange like interactions between Mn atoms mediated by Ni. [ABSTRACT FROM AUTHOR]

We report on the electronic structure of the perovskite oxide CaCrO3 using valence-band, core-level, and Cr 2p-3d resonant photoemission spectroscopy (PES). Despite its antiferromagnetic order, a clear Fermi edge characteristic of a metal with dominant Cr 3d character is observed in the valence-band spectrum. The Cr 3d single-particle density of states are spread over 2 eV, with the photoemission spectral weight distributed in two peaks centered at ~1.2 and 0.2 eV below EF, suggestive of the coherent and incoherent states resulting from strong electron-electron correlations. Resonant PES across the Cr 2p-3d threshold identifies a "two-hole" correlation satellite and yields an on-site Coulomb energy U~ 4.8 eV. The metallic DOS at EF is also reflected through the presence of a well-screened feature at the low binding energy side of the Cr 2p core-level spectrum. X-ray-absorption spectroscopy at Cr L3,2 and O K edges exhibit small temperature-dependent changes that point toward a small change in Cr-O hybridization. The Cr 2p core-level spectrum can be reproduced using cluster model calculations that include a charge transfer from the metallic screening channel at EF. The overall results indicate that CaCrO3 is a strongly hybridized antiferromagnetic metal, lying in the regime intermediate to Mott-Hubbard and charge-transfer systems. [ABSTRACT FROM AUTHOR]

The local structural distortions arising as a consequence of increasing Mn content in Ni2Mn1+xIn1-x (x=0, 0.3, 0.4, 0.5, and 0.6) and its effect on martensitic transformation have been studied using extended x-ray absorption fine structure (EXAFS) spectroscopy. Using the room temperature EXAFS at the Ni and Mn K-edges in the above compositions, the changes associated with respect to the local structure of these absorbing atoms are compared. It is seen that in the alloys exhibiting martensitic transformation (x≥0.4) there is a significant difference between the Ni–In and Ni–Mn bond lengths even in the austenitic phase indicating atomic volume to be the main factor in inducing martensitic transformation in Ni–Mn–In Heusler alloys. [ABSTRACT FROM AUTHOR]

We have studied the effect of magnetic field on a nonstoichiometric Heusler alloy Ni50Mn35In15 that undergoes a martensitic as well as a magnetic transition near room temperature. Temperature dependent magnetization measurements demonstrate the influence of magnetic field on the structural phase transition temperature. From the study of magnetization as a function of applied field, we show the occurrence of inverse-magnetocaloric effect associated with this magneto-structural transition. The magnetic entropy change attains a value as high as 25 J/kg K (at 5 T field) at room temperature as the alloy transforms from the austenitic to martensitic phase with a concomitant magnetic ordering. [ABSTRACT FROM AUTHOR]

We have investigated the structure, transport and magnetic properties of Ni2MnSb0.5Al0.5 Heusler alloy. Structural analysis using x-ray diffraction and scanning electron microscopy has confirmed Ni2MnSb0.5Al0.5 to be a natural composite of Ni2MnSb and Ni2MnAl phases, regardless of annealing conditions. This composite has a dendritic microstructure formed by the phase separation during solidification. The electronic phase separation was confirmed using x-ray near edge absorption spectroscopy, recorded at Mn and Ni K-edge and supported by ab-initio calculations of the same using multiple scattering theory. A thorough characterization of this novel composite form of Ni2MnSb0.5Al0.5 Heusler alloy has been carried out by recording its magnetic and transport properties including electrical resistivity, thermal conductivity, and heat capacity. The composite micro-structure of this system plays a crucial role in drastically reducing its thermal conductivity value, while maintaining its metallic character. Unlike many oxide composites, the magnetic properties of the Ni2MnSb0.5Al0.5 cannot be considered as the volume average of the characteristics of the two phases, rather it shows a long range ferromagnetic order with Curie temperature of 334 K and magnetic moment of 2.52 /f.u. [ABSTRACT FROM AUTHOR]