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Chirality, which is a fundamental property of symmetry, can produce unique electronic and magnetic properties. The problem is that many of the chiral inorganic compounds form a racemic mixture consisting of right- and left-handed enantiomers. Here, the authors succeeded in growing the enantiopure single crystal of Nd-based monoaxial chiral magnet, demonstrating the nontrivial magnetic phase diagram in this rare-earth chiral magnet with the DM interaction. This ternary rare-earth platinum boride system provides an attractive platform for examining chiral magnetism and the role of DM interaction.

We report an unconventional class of pressure-induced quantum phase transitions, possessing two bicritical points at 6.25 GPa in URhSn. This unique transformation accompanies a Fermi surface reconstruction, demarcating competing ordered phases suitably described with a localized and itinerant description of the magnetic $5f$ electrons. Ferromagnetic fluctuations over a wide range of temperatures and pressures in the pressure-induced low temperature phase are evidenced by a robust ${T}^{5/3}$ temperature dependence of resistivity up to 11 GPa, which is a characteristic of an elusive marginal Fermi-liquid state.

${\mathrm{CeIr}}_{3}$ is a Ce-based superconductor with a superconducting transition temperature ${T}_{\mathrm{c}}=3.4$ K in an intermediate-valence state. We grew high-quality single crystals of ${\mathrm{CeIr}}_{3}$ using the Czochralski method, and measured the electrical resistivity, magnetic torque, and specific heat. The anisotropy of the superconducting upper critical field ${H}_{\mathrm{c}2}$ was determined. The temperature dependence of ${H}_{\mathrm{c}2}$, obtained from the resistivity measurements, suggests the multiband character of the superconductivity in ${\mathrm{CeIr}}_{3}$. Different field-angle dependencies of ${H}_{\mathrm{c}2}$ in electrical transport and thermodynamic measurements indicate the robust surface effect in the bulk superconductivity of ${\mathrm{CeIr}}_{3}$. We analyzed the surface superconductivity based on simple models to reveal the bulk superconducting properties. Our results support the isotropic bulk superconducting state and robust surface superconductivity in ${\mathrm{CeIr}}_{3}$ single crystals.

The physical properties of URhSn with quasi-kagome structure are studied using single-crystalline samples via electrical resistivity, magnetic susceptibility, heat capacity, thermal expansion, and high-field magnetization measurements. Remarkable magnetic anisotropy is found in the ferromagnetic (FM) state below ${T}_{\mathrm{C}}=16\phantom{\rule{4pt}{0ex}}\mathrm{K}$ as well as in the ordered state between ${T}_{\mathrm{C}}$ and ${T}_{\mathrm{O}}=54\phantom{\rule{4pt}{0ex}}\mathrm{K}$, where the easy and hard magnetization directions are the hexagonal [0001] and $[10\overline{1}0]$ axes. In the paramagnetic state, the magnetic susceptibility shows a Curie-Weiss behavior; the Weiss temperatures are positive and negative for [0001] and $[10\overline{1}0]$, respectively, indicating the presence of both FM and antiferromagnetic (AFM) correlations. The entropy release for $5f$ electrons is approximately $R\phantom{\rule{0.16em}{0ex}}\mathrm{ln}3$ at ${T}_{\mathrm{O}}$. The thermal expansion coefficient is strongly anisotropic around ${T}_{\mathrm{O}}$ between the hexagonal basal plane and the [0001] axis, indicating its remarkable anisotropic magnetoelastic response and uniaxial stress dependences. Interestingly, the magnetic field response of the higher-temperature ordered state is unusual: ${T}_{\mathrm{O}}(H)$ increases and the heat-capacity jump is enhanced with the magnetic field for $H\phantom{\rule{0.16em}{0ex}}||\phantom{\rule{4pt}{0ex}}[0001]$. Based on the established thermodynamic evidence for the second-order transition at ${T}_{\mathrm{O}}(H)$, a plausible scenario is the occurrence of a canted AFM ordering or a conical state under magnetic fields, which is stabilized when coupled with field-induced magnetic moments along the [0001] axis. Another possibility is the occurrence of quadrupole ordering at ${T}_{\mathrm{O}}(H)$.

We report on the observation of a nonsaturating, extremely large magnetoresistance (XMR) and the Fermi surface topology of a high quality $\mathrm{W}{\mathrm{Si}}_{2}$ single crystal grown by the Czochralski method. The magnetoresistance at $T=2\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ reaches a value $\ensuremath{\approx}{10}^{5}%$ in 14 T magnetic field with no sign of saturation. The Hall resistivity data of $\mathrm{W}{\mathrm{Si}}_{2}$ was found to be highly anisotropic. The analysis of magnetoconductivity data of $\mathrm{W}{\mathrm{Si}}_{2}$ revealed a near compensation of charge carrier with relatively low carrier density as compared to that of a normal metal. The observed anisotropic Hall resistivity in $\mathrm{W}{\mathrm{Si}}_{2}$ is due to the presence of multiple bands and Fermi pockets responsible for the transport phenomena in it. The extremely large carrier mobility and near compensation of charge carriers are responsible for the nonsaturating XMR behavior in $\mathrm{W}{\mathrm{Si}}_{2}$ crystal. The band structure calculation and de Haas-van Alphen effect measurement depict a cylindrical Fermi surface from which the associated quantum parameters have been obtained. The magnetotransport data of $\mathrm{W}{\mathrm{Si}}_{2}$ along both the crystallographic directions follows the universal temperature-field triangular phase diagram as observed in other materials exhibiting XMR behavior.

We report the single-crystal growth of the noncentrosymmetric cubic heavy-fermion paramagnet ${\mathrm{UPt}}_{5}$ and comparative Fermi surface studies of de Haas-van Alphen (dHvA) experiments and theoretical band calculations. We also present the results of single-crystal x-ray diffraction, electrical resistivity, heat capacity, and magnetization measurements using single crystals of ${\mathrm{UPt}}_{5}$. The dHvA experiments reveal nearly spherical split hole Fermi surfaces and largely split electron Fermi surfaces, which are in agreement with the results of a band-structure calculation. The largely split electron Fermi surfaces may be understood through the antisymmetric spin-orbit interaction derived from U-$5f$ and Pt-$5d$ electrons. We explain the observed unexpected dHvA frequencies quasiquantitatively based on orbital crossing using the coupled network analysis in the split hole Fermi surface pair. Furthermore, the temperature dependence of the dHvA amplitude reveals enhanced cyclotron effective masses of up to $29{m}_{0}$ and a peculiar anisotropic effective mass in the paramagnetic cubic heavy-fermion ${\mathrm{UPt}}_{5}$.

Background: Dyspepsia is one amongst the most common clinical disorder. Dyspepsia could be a common clinical problem. The common organic causes of dyspepsia include peptic ulceration, esophagitis and cancer. However, controversy remains over the role of endoscopy in patients with dyspepsia. Objective: Objective of the study was to evaluate the role of endoscopy in patients presenting with dyspepsia, assess chief complaints and endoscopic findings in each patient and making diagnosis for better and early treatment. Material and Method: This retrospective was conducted in the Department of Surgery, Muzaffarnagar Medical College and Associated Hospital from January 2021 to January 2022. The clinical data were collected after detailed history and informed consent. Results A total of 100 cases were enrolled for this study. Fifty percent were male. The mean age was 38.83±15.33 years. Forty eight patients were vegetarian, forty patients were non-vegetarian and twelve patients were both vegetarian and non-vegetarian. Nineteen patients (19%) had a history of smoking, 18% had the co-morbid condition and 05 (5%) were consuming alcohol. The endoscopy findings included gastritis in 38 cases, Gastro-esophageal reflux disease in 39 cases, 12 subject having Hiatus Hernia, duodenitis in 6 patients, 30 cases were RUT positive and malignancy in 2 patients. Conclusion: Patients with dyspepsia should undergo endoscopy. Endoscopy revealed normal findings or miscellaneous irrelevant findings in the majority of patients.

Single crystals of the new compound CeCu 0.18 Al 0.24 Si 1.58 have been grown by high-temperature solution growth method using a eutectic Al-Si mixture as flux. This compound is derived from the binary CeSi 2 (tetragonal α-ThSi 2 -type, Pearson symbol tI 12, space group I 4 1 /amd ) obtained by partial substitution of Si by Cu and Al atoms but showing full occupation of the Si crystal site (8 e ). While CeSi 2 is a well-known valence-fluctuating paramagnetic compound, the CeCu 0.18 Al 0.24 Si 1.58 phase orders ferromagnetically at T C =9.3 K. At low temperatures the easy-axis of magnetization is along the a- axis, which re-orients itself along the c -axis above 30 K. The presence of hysteresis in the magnetization curve, negative temperature coefficient of resistivity at high temperatures, reduced jump in the heat capacity and a relatively lower entropy released up to the ordering temperature, and enhanced Sommerfeld coefficient (≈100 mJ/mol K 2 ) show that CeCu 0.18 Al 0.24 Si 1.58 is a Kondo lattice ferromagnetic, moderate heavy fermion compound. Analysis of the high temperature heat capacity data in the paramagnetic region lets us infer that the crystal electric field split doublet levels are located at 178 and 357 K, respectively, and Kondo temperature (8.4 K) is of the order of T C in CeCu 0.18 Al 0.24 Si 1.58 .

The physical properties of the single-crystalline ${\mathrm{U}}_{2}{\mathrm{Ir}}_{3}{\mathrm{Si}}_{5}$, a new ternary uranium compound with ${\mathrm{U}}_{2}{\mathrm{Co}}_{3}{\mathrm{Si}}_{5}$-type orthorhombic structure, are investigated by means of magnetic susceptibility $\ensuremath{\chi}(T)$, specific heat $C(T)$, electrical resistivity $\ensuremath{\rho}(T)$, and high-field magnetization $M(H,T)$ measurements. ${\mathrm{U}}_{2}{\mathrm{Ir}}_{3}{\mathrm{Si}}_{5}$ undergoes an antiferromagnetic transition at ${T}_{N}=36$ K followed by a first-order phase transition at ${T}_{0}=25.5$ K. The sharp peak in $C(T)$ at ${T}_{0}$ and the obvious hysteresis behavior in $\ensuremath{\chi}(T),\ensuremath{\rho}(T)$, and $M(H,T)$ around ${T}_{0}$ provide strong evidence for the first-order phase transition. The $\ensuremath{\rho}(T)$ measurements along the $a$ and $b$ axes reveal the negative temperature coefficients of resistance over a wide temperature range, which can be understood based on the semiconductorlike narrow band gap model or the Kondo effect. The $M(H)$ curve measured at 4.2 K along the $b$ axis shows three-step metamagnetic transitions within a narrow field region around 200 kOe and a large hysteresis near the first transition field, while the ${M}_{H\ensuremath{\parallel}a}(H)$ and ${M}_{H\ensuremath{\parallel}c}(H)$ curves show no transitions up to 560 kOe suggesting the strong magnetic anisotropy. A possible mechanism of the first-order phase transition at ${T}_{0}$ is the occurrence of a magnetic quadrupolar order, resulting from the quasi-one-dimensional uranium zigzag chain.

We have grown the single crystal of PrRhAl$_4$Si$_2$, which crystallizes in the tetragonal crystal structure. From the low temperature physical property measurements like, magnetic susceptibility, magnetization, heat capacity and electrical resistivity, we found that this compound does not show any magnetic ordering down to 70~mK. Our crystal field calculations on the magnetic susceptibility and specific heat measurements reveal that the 9-fold degenerate $(2J+1)$ levels of Pr atom in PrRhAl$_4$Si$_2$, splits into 7 levels, with a singlet ground state and a well separated excited doublet state at 123~K, with a overall level splitting energy of 320~K., 5 figures

A new ternary uranium germanide U2Rh3Ge5 has been successfully synthesized and investigated by means of magnetic susceptibility χ(T, H), isothermal magnetization M(T, H), electrical resistivity ρ(T), and specific heat C(T, H) measurements. This compound is found to crystallize in the U2Co3Si5-type orthorhombic structure. The low-field χ(T) shows a clear peak at T N = 41.5 K corresponding to an antiferromagnetic transition. The M(H) curve measured up to 70 kOe exhibits an H-linear behavior at 2 K with very small induced magnetic moments, while it shows upward curvature with increasing temperature, implying the possible presence of a metamagnetic transition in high-field region above 70 kOe. As the temperature decreases, ρ(T) increases slowly at T > T N and decreases rapidly at T < T N, which can be understood based on a semiconductor-like narrow band gap model (or the c-f hybridization effect) and an antiferromagnetic spin-wave model, respectively. No evidence of heavy-fermion behavior or superconductivity transition is observed at temperatures as low as 0.4 K. The obtained experimental results are discussed by comparing with those reported for the isomorphic compound U2Ir3Si5 and the quasi-isomorphic compound U2Rh3Si5.

We succeeded in growing high-quality single crystals of ThCu2Si2 with the ThCr2Si2-type tetragonal structure by the Sn-flux method and measured the electrical resistivity, specific heat, and de Haa...

We report the investigation of the magnetic susceptibility (χ), specific heat (CP), electrical resistivity (ρ) and magnetoresistance (MR) studies of the compound Ce2Ru3Ge5. Ce2Ru3Ge5 crystallizes i...

We report the single-crystal growth of the non-centrosymmetric paramagnet U3Ni3Sn4 by the Bridgman method and the Fermi surface properties detected by de Haas-van Alphen (dHvA) experiments. We have also investigated single-crystal U3Ni3Sn4 by single-crystal X-ray diffraction, magnetization, electrical resistivity, and heat capacity measurements. The angular dependence of the dHvA frequencies reveals many closed Fermi surfaces, which are nearly spherical in topology. The experimental results are in good agreement with local density approximation (LDA) band structure calculations based on the 5f-itinerant model. The band structure calculation predicts many Fermi surfaces, mostly with spherical shape, derived from 12 bands crossing the Fermi energy. To our knowledge, the splitting of Fermi surfaces due to the non-centrosymmetric crystal in 5f-electron systems is experimentally detected for the first time. The temperature dependence of the dHvA amplitude reveals a large cyclotron effective mass of up to 35m0, indicating the heavy electronic state of U3Ni3Sn4 due to the proximity of the quantum critical point. From the field dependence of the dHvA amplitude, a mean free path of conduction electrons of up to 1950A is detected, reflecting the good quality of the grown crystal. The small splitting energy related to the antisymmetric spin-orbit interaction is most likely due to the large cyclotron effective mass., 8 pages, 8 figures, accepted for publication in J. Phys. Soc. Jpn

We report a comprehensive investigation of the crystal structure and magnetic behavior of the $S=1$ compound ${\mathrm{Ba}}_{2}\mathrm{Ni}{({\mathrm{PO}}_{4})}_{2}$ with a honeycomblike topology of the spin lattice. Magnetic susceptibility and specific-heat data reveal two successive transitions at ${T}_{N1}=5\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ and ${T}_{N2}=4.6\phantom{\rule{0.28em}{0ex}}\mathrm{K}$. Additionally, these data demonstrate a broad peak at ${T}_{max}\ensuremath{\sim}8\phantom{\rule{0.28em}{0ex}}\mathrm{K}$, indicative of the short-range magnetic order above ${T}_{N1}$, whereas below ${T}_{N1}$ field-induced transitions around 4 and 10 T are identified from the magnetization measurements. Neutron diffraction in zero field establishes stripe antiferromagnetic order below ${T}_{N2}$ with the ordered moment of $1.75(8){\ensuremath{\mu}}_{B}/{\mathrm{Ni}}^{2+}$ at 1.5 K. Density-functional band-structure calculations reveal the leading interaction ${J}_{3}=3.5\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ running perpendicular to the honeycomb planes, and weaker interactions ${J}_{1}=0.5\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ and ${J}_{4}=1.8\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ within the honeycomb planes, whereas the stripe order is stabilized by the diagonal interlayer interaction ${J}_{2}=1.3\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ that frustrates ${J}_{1}$. This is in contrast to the usually expected scenario where the competing second- and third-neighbor interactions on the honeycomb lattice stabilize the stripe order. The ${\mathrm{Ni}}^{2+}$ ions feature a sizable easy-plane anisotropy $A\ensuremath{\simeq}10.5\phantom{\rule{0.28em}{0ex}}\mathrm{K}$, but the position of the easy plane changes from one atom to another, thus amplifying magnetic frustration.

We report the results of 151Eu Mossbauer spectroscopy on EuPtSi with a chiral structure belonging to the P213 (#198) space group at zero magnetic field. The paramagnetic single absorption forms a m...

We present here a neutron diffraction study, both in zero field and as a function of magnetic field, of the magnetic structure of the tetragonal intermetallic ${\mathrm{EuNiGe}}_{3}$ on a single crystalline sample. This material is known to undergo a cascade of transitions, first at 13.2 K towards an incommensurate modulated magnetic structure, then at 10.5 K to an antiferromagnetic structure. We show here that the low-temperature phase presents a spiral moment arrangement with wave vector $\mathbit{k}=(\frac{1}{4},\ensuremath{\delta},0)$. For a magnetic field applied along the tetragonal $c$ axis, the square root of the scattering intensity of the (1 0 1) reflection matches very well the complex metamagnetic behavior of the magnetization along $c$ measured previously. For the magnetic field applied along the $b$ axis, two magnetic transitions are observed below the transition to a fully polarized state.

The low-temperature magnetic properties of Ce5Si4 with a chiral structure have been studied by electrical resistivity, heat capacity, and magnetization measurements using single-crystalline samples...

We present detailed investigations on single crystals of quaternary EuRhAl4Si2 and EuIrAl4Si2. The two compounds order antiferromagnetically at TN1 = 11.7 and 14.7 K, respectively, each undergoing two magnetic transitions. The magnetic properties in the ordered state present a large anisotropy despite Eu2+being an S-state ion for which the single-ion anisotropy is expected to be weak. Two features in the magnetization measured along the c-axis are prominent. At 1.8 K, a ferromagnetic-like jump occurs at very low field to a value one third of the saturation magnetization (1/3 M0) followed by a wide plateau up to 2 T for Rh and 4 T for Ir-compound. At this field value, a sharp hysteretic spin-flop transition occurs to a fully saturated state (M0). Surprisingly, the magnetization does not return to origin when the field is reduced to zero in the return cycle, as expected in an antiferromagnet. Instead, a remnant magnetization 1/3 M0 is observed and the magnetic loop around the origin shows hysteresis. This suggests that the zero field magnetic structure has a ferromagnetic component and we present a model with up to third neighbor exchange and dipolar interaction which reproduces the magnetization curves and hints to an “up-up-down” magnetic structure in zero field.

International audience; EuAl2Si2 is known to crystallize in the CaAl2Si2-type trigonal structure. We have grown single crystals of EuAl2Si2 by flux method, using Al-Si eutectic (87.8% Al) as self-flux, and investigated their anisotropic magnetic properties by means of magnetization, electrical resistivity and heat capacity in zero and applied magnetic fields, and 151Eu Mössbauer spectroscopy. Magnetic susceptibility data show an antiferromagnetic transition at TN = 33.3 K in agreement with the previously reported value on polycrystalline sample. The isothermal magnetization at 2 K measured along and perpendicular to the c-axis shows anisotropic behaviour, which is rather unexpected as Eu2+ is an S-state ion. The spin flip fields along the two directions are 2.8 and 4.8 T, respectively, while two closely spaced spin-flop transitions in the ab-plane are observed near 1.4 and 1.6 T. The electrical resistivity shows an upturn between TN and 60 K as the temperature is lowered below ~ 60 K, suggesting the presence of antiferromagnetic correlations in the paramagnetic state. Magnetoresistivity at 2 K in 14 T is nearly 1070 % for H // [0001]. The results of heat capacity and 151Eu Mössbauer spectroscopy are in conformity with a bulk transition at 33.3 K.

We report the magnetic properties of two Eu based compounds, single crystalline EuIrGe$_3$ and EuRhGe$_3$, inferred from magnetisation, electrical transport, heat capacity and $^{151}$Eu M\"{o}ssbauer spectroscopy. These previously known compounds crystallise in the non-centrosymmetric, tetragonal, $I4mm$, BaNiSn$_3$-type structure. Single crystals of EuIrGe$_3$ and EuRhGe$_3$ were grown using high temperature solution growth method using In as flux. EuIrGe$_3$ exhibits two magnetic orderings at $T_{\rm N1}$ = 12.4 K, and $T_{\rm N2}$ = 7.3 K. On the other hand EuRhGe$_3$ presents a single magnetic transition with a $T_{\rm N}$ = 12 K. $^{151}$Eu M\"{o}ssbauer spectra present evidence for a cascade of transitions from paramagnetic to incommensurate amplitude modulated followed by an equal moment antiferromagnetic phase at lower temperatures in EuIrGe$_3$, the transitions having a substantial first order character. On the other hand the $^{151}$Eu M\"{o}ssbauer spectra at 4.2 and 9 K in EuRhGe$_3$ present evidence of a single magnetic transition. In both compounds a superzone gap is observed for the current density $J\parallel$ [001], which enhances with transverse magnetic field. The magnetisation measured up to 14 T shows the occurrence of field induced transitions, which are well documented in the magnetotransport data as well. The magnetic phase diagram constructed from these data is complex, revealing the presence of many phases in the $H-T$ phase space.

International audience; Single crystals of EuNiGe 3 crystallizing in the non-centrosymmetric BaNiSn 3-type structure have been grown using In flux, enabling us to explore the anisotropic magnetic properties which was not possible with previously reported polycrystalline samples. The EuNiGe 3 single crystalline sample is found to order antiferromagnetically at 13.2 K as revealed from the magnetic susceptibility, heat capacity and electrical resistivity data. The low temperature magnetization M(H) is distinctly different for field parallel to ab-plane and c-axis; the ab-plane magnetization varies nearly linearly with field before the occurrence of an induced ferromagnetic phase (spin-flip) at 6.2 Tesla; on the other hand M(H) along the c-axis is accompanied by two metamagnetic transitions followed by a spin-flip at 4.1 T. A model including anisotropic exchange and dipole-dipole interactions reproduces the main features of magnetization plots but falls short of full representation. (H,T) phase diagrams have been constructed for the field applied along the principal directions. From the 151 Eu Mössbauer spectra, we determine that the 13.2 K transition leads to an incommensu-rate antiferromagnetic intermediate phase followed by a transition near 10.5 K to a commensurate antiferromagnetic configuration.

Single crystals of the title compounds are prepared from the elements using an eutectic Al—Si mixture as a flux (alumina crucible, 1100 °C, 24 h).

Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013); International audience; We have carried out detailed magnetization, heat capacity, electrical resistivity and 151 Eu Mössbauer measurements on a single crystal of Eu 3 Rh 4 Sn 13 , grown by high temperature solution method using tin as a solvent. Despite its cubic symmetry the compound exhibits anisotropic magnetic behaviour at low temperatures, ordering antiferromagnetically at 11.2 K. The entropy associated with the magnetic transition is in conformity with the divalent state of the Eu ions. Based on the susceptibility data magnetic phase diagrams are constructed for field parallel to principal crystallographic axes. A magnetic hyperfine field of 28 T is obtained from the hyperfine field split 151 Eu Mössbauer spectrum at 4.2 K.

Single crystals of the quaternary europium compounds EuRhAl4Si2 and EuIrAl4Si2 were synthesized by using the Al-Si binary eutectic as a flux. The structure of the two quaternary compounds has been refined by single crystal X-ray diffraction. Both compounds are stoichiometric and adopt an ordered derivative of the ternary KCu4S3 structure type (tetragonal tP8, P4/mmm). The two compounds reported here represent the first example of a quaternary and truly stoichiometric 1:1:4:2 phase crystallizing with this structure type. In light of our present results, the structure of the BaMg4Si3 compound given in literature as representing a new prototype is actually isotypic with the KCu4S3 structure. Local spin density approximation including the Hubbard U parameter (LSDA + U) calculations show that Eu ions are in the divalent state, with a significant hybridization between the Eu 5d, Rh (Ir) 4d (5d), Si 3p and Al 3p states. Magnetic susceptibility measured along the [001] direction confirms the divalent nature of the Eu ions in EuRhAl4Si2 and EuIrAl4Si2, which order magnetically near ∼11 and ∼15 K, respectively.

The anisotropic magnetic properties of the antiferromagnetic compound CePd$_2$Ge$_2$, crystallizing in the tetragonal crystal structure have been investigated in detail on a single crystal grown by Czochralski method. From the electrical transport, magnetization and heat capacity data, the N\'{e}el temperature is confirmed to be 5.1 K. Anisotropic behaviour of magnetization and resistivity is observed along the two principal crystallographic directions viz., [100] and [001]. The isothermal magnetization measured in the magnetically ordered state at 2 K exhibits a spin re-orientation at 13.5 T for field applied along [100] direction, whereas the magnetization was linear along the [001] direction attaining a value of 0.94 $\mu_{\rm B}$/Ce at 14 T. The reduced value of the magnetization is attributed to the crystalline electric field (CEF) effects. A sharp jump in the specific heat at the magnetic ordering temperature is observed. After subtracting the phononic contribution, the jump in the heat capacity amounts to 12.5 J/K mol which is the expected value for a spin ${1}{2}$ system. From the CEF analysis of the magnetization data the excited crystal field split energy levels were estimated to be at 120 K and 230 K respectively, which quantitatively explain the observed Schottky anomaly in the heat capacity. A magnetic phase diagram has been constructed based on the field dependence of magnetic susceptibility and the heat capacity data., Comment: 15 pages, 8 figures

We report the synthesis and the magnetic properties of single crystalline CeRhAl$_4$Si$_2$ and CeIrAl$_4$Si$_2$ and their non magnetic La-analogs. The single crystals of these quaternary compounds were grown using Al-Si binary eutectic as flux. The anisotropic magnetic properties of the cerium compounds were explored in detail by means of magnetic susceptibility, isothermal magnetization, electrical resistivity, magnetoresistivity and heat capacity measurements. Both CeRhAl$_4$Si$_2$ and CeIrAl$_4$Si$_2$ undergo two antiferromagnetic transitions, first from the paramagnetic to an antiferromagnetic state at $T_{\rm N1}$~=~12.6~K and 15.5~K, followed by a second transition at lower temperatures $T_{\rm N2}$~=~9.4~K and 13.8~K, respectively. The paramagnetic susceptibility is highly anisotropic and its temperature dependence in the magnetically ordered state suggests the $c$-axis to be the relatively easy axis of magnetization. Concomitantly, isothermal magnetization at 2~K along the $c$-axis shows a sharp spin-flop transition accompanied by a sizeable hysteresis, while it varies nearly linearly with field along the [100] direction up to the highest field 14~T, of our measurement. The electrical resistivity provides evidence of the Kondo interaction in both compounds, inferred from its $-lnT$ behavior in the paramagnetic region. The heat capacity data confirm the bulk nature of the two magnetic transitions in each compound, and further confirm the presence of Kondo interaction by a reduced value of the entropy associated with the magnetic ordering. From the heat capacity data below 1~K, the coefficient of the linear term in the electronic heat capacity, $\gamma$, is inferred to be 195.6 and 49.4~mJ/mol K$^2$ in CeRhAl$_4$Si$_2$ and CeIrAl$_4$Si$_2$, respectively classifying these materials as moderate heavy fermion compounds., Comment: 16 pages, 11 Figures

We report on the physical properties of single crystalline EuRhSi$_3$ and polycrystalline EuIrSi$_3$, inferred from magnetisation, electrical transport, heat capacity and $^{151}$Eu M\"ossbauer spectroscopy. These previously known compounds crystallise in the tetragonal BaNiSn$_3$-type structure. The single crystal magnetisation in EuRhSi$_3$ has a strongly anisotropic behaviour at 2 K with a spin-flop field of 13 T, and we present a model of these magnetic properties which allows the exchange constants to be determined. In both compounds, specific heat shows the presence of a cascade of two close transitions near 50 K, and the $^{151}$Eu M\"ossbauer spectra demonstrate that the intermediate phase has an incommensurate amplitude modulated structure. We find anomalously large values, with respect to other members of the series, for the RKKY N\'eel temperature, for the spin-flop field (13 T), for the spin-wave gap ($\simeq$ 20-25 K) inferred from both resistivity and specific heat data, for the spin-disorder resistivity in EuRhSi$_3$ ($\simeq 35$ $\mu$Ohm.cm) and for the saturated hyperfine field (52 T). We show that all these quantities depend on the electronic density of states at the Fermi level, implying that the latter must be strongly enhanced in these two materials. EuIrSi$_3$ exhibits a giant magnetoresistance ratio, with values exceeding 600 % at 2 K in a field of 14 T., Comment: 6 pages, 8 figures

We present a simple fabrication technique for lateral nanowire wrap-gate devices with high capacitive coupling and field-effect mobility. Our process uses e-beam lithography with a single resist-spinning step, and does not require chemical etching. We measure, in the temperature range 1.5-250 K, a subthreshold slope of 5-54 mV/decade and mobility of 2800-2500 $cm^2/Vs$ -- significantly larger than previously reported lateral wrap-gate devices. At depletion, the barrier height due to the gated region is proportional to applied wrap-gate voltage., Comment: 3 pages, 3 figures