Magnetic and Transport Properties of PrNi Single Crystal

Frequency dependence of χ (T ), different position of a maximum in χ (T ) for different crystal orientations, hysteretic behavior between magnetization measurements in zero-field cooling and field coolding regime are attributed to strong magneto-crystalline anisotropy of PrNi ferromagnetic single crystal with T C = 20.5 K, which is driven by crystal field effect. Applied pressure shifts T C to higher temperatures (dT C /dp = 1 K/GPa). Susceptibility follows the Curie-Weiss law except for b-axis, which is hard magnetic axis. An anisotropic behavior was seen in resistivity measurements with the largest difference between b-axis and c-axis. Resistivity below TC can be described by power law with ρ ∼ T 2.24 and is field dependent with a positive magnetoresistance

Magnetic and Transport Properties of PrNi Single Crystal

Frequency dependence of χ"(T), different position of a maximum in χ"(T) for different crystal orientations, hysteretic behavior between magnetization measurements in zero-field cooling and field coolding regime are attributed to strong magneto-crystalline anisotropy of PrNi ferromagnetic single crystal with $T_C$=20.5 K, which is driven by crystal field effect. Applied pressure shifts $T_C$ to higher temperatures ($dT_C$/dp=1 K/GPa). Susceptibility follows the Curie-Weiss law except for b-axis, which is hard magnetic axis. An anisotropic behavior was seen in resistivity measurements with the largest difference between b-axis and c-axis. Resistivity below $T_C$ can be described by power law with $ρT^{2.24}$ and is field dependent with a positive magnetoresistance

Magnetism in NdMnO3+δNdMnO_{3+δ} Studied by the Single Crystal Neutron Diffraction

We present the single crystal neutron diffraction experiment performed on the $NdMnO_{3+δ}$ compound. The aim of the experiment was to study/revisit the magnetic structure of the compound. We have confirmed the ordering of Mn sublattice below $T_{N}$=85.5 K and confirmed that the Nd sublattice orders below $T_{1}$ ≈ 20 K with Nd moments aligned parallel to the b-axis

Anisotropy of Susceptibility and Optical investigation of the Antiferromagnetic phase Transition in U1−x\text{}_{1-x}Cex\text{}_{x}Ru2\text{}_{2}Si2\text{}_{2}

Temperature dependence of magnetic susceptibility of U$\text{}_{1-x}$Ce$\text{}_{x}$Ru $\text{}_{2}$Si$\text{}_{2}$ single crystals (x=0, 0.025, 0.05, 0.075) has been studied at temperatures from 4.2 K up to room temperature and in magnetic fields applied along and perpendicular to the c-axis. The attention was paid to anomalies connected with the antiferromagnetic phase transition, which are present in crystals with x≤0.05. Far-infrared measurements of U$\text{}_{0.99}$Ce$\text{}_{0.01}$ Ru$\text{}_{2}$Si$\text{}_{2}$ single crystal have been studied for the first time. The measurements support the assumption that the origin of magnetic ordering in U$\text{}_{0.99}$Ce$\text{}_{0.01}$Ru$\text{}_{2}$Si$\text{}_{2}$ is the same as in heavy-fermion superconductor URu$\text{}_{2}$Si$\text{}_{2}$ and can be interpreted as being due to a spin-density-wave gap

Effect of Pressure on Magnetic Properties of Hexacyanochromates

We present the study of pressure effect on magnetic properties of $TM^{2+}_3[Cr^{III}(CN)_6]_2 \cdot nH_2O$ ferrimagnets and ferromagnets (TM = Cr and Co) under pressures up to 0.9 GPa. Applied pressure strengthens super-exchange interaction in $Cr^{2+}$-prussian blue analogues with dominant antiferromagnetic interaction $J_{AF}$ leading to increase in the Curie temperature $T_C$ (ΔT_c/Δp = 29.0 K/GPa) and reduces $T_C$ of $Co^{2+}$-prussian blue analogues with dominant ferromagnetic interaction $J_F$ (Δ$T_c$/Δp = -1.8 K/GPa). The rise of $J_{AF}$ interaction is attributed to the enhanced value of the single electron overlapping integral S. On the other hand, the applied pressure slightly affects bonding angles between magnetic ions mediated by the cyano-bridge and reduces the strength of magnetic coupling. Changes of the magnetization curve with pressure can be attributed to changes of magnetic anisotropy. The reduction of magnetization with pressure observed on $Cr^{2+}$-prussian blue analogues can be explained by pressure induced transition from $Cr^{2+}$ high spin state to $Cr^{2+}$ low spin state. All pressure induced changes are reversible

Magnetic Properties of Milled and Thermal Relaxed YBa2\text{}_{2} (Cu1−x\text{}_{1-x}Fex\text{}_{x})3\text{}_{3}Oy\text{}_{y}

The influence of the mechanical milling and subsequent thermal relaxation on magnetic and superconducting behaviour of YBa$\text{}_{2}$(Cu$\text{}_{1-x}$Fe $\text{}_{x}$)$\text{}_{3}$O$\text{}_{y}$ system has been studied. Two methods of heat treatment were used: Set I - slow cooling from 980°C in flowing O$\text{}_{2}$ and Set II - reducing at 770°C in flowing Ar$\text{}_{2}$ followed by reoxidation in flowing O$\text{}_{2}$ below 400°C. The transition to superconductivity, diamagnetic response, critical current density and the effective magnetic moment in the normal state have been estimated. Our measurements indicate that the reducing atmosphere preparation is less detrimental on superconducting properties. The results are discussed in terms of occupancy Cu sites by Fe and redistribution of oxygen atoms

Magnetic and Transport Properties of La0.67Pb0.33(Mn1−xCox)O3La_{0.67}Pb_{0.33}(Mn_{1-x}Co_x)O_3

Detailed studies of temperature dependences of magnetization, AC susceptibility and electrical resistance were performed on $La_{0.67}Pb_{0.33}(Mn_{1-x}Co_x)O_3$ ceramics with x = 0.01 and 0.1. Typical features of both compounds are the hysteretic behavior between the zero-field-cooled magnetization regime and the field-cooled magnetization regime, a very weak field dependence of a maximum in zero-field-cooled magnetization and practically no frequency dependence of the peak in AC susceptibility χ"(T). Anomalies in the electrical resistance connected with the ferromagnetic transition at $T_C$, the insulator-metal transitions at $T_p$ and the re-entrant metal-isolator transition at T* are field dependent pointing to magnetic origin of these transitions. Colossal magnetoresistance was observed in both compounds

Magnetic Relaxation and Memory Effect in Nickel-Chromium Cyanide Nanoparticles

The low temperature dynamics of a magnetic nanoparticle system $Ni_3[Cr(CN)_6]_2$ with an average nanoparticles size of 4 nm was studied. Using different temperature and field protocols memory phenomena were studied by the DC magnetization and magnetic relaxation measurements of the system at temperatures below $T_m$ = 19 K. Aging experiments show an absence of any waiting time dependence in the magnetization relaxation due to a field change after zero field and field cooling. This observation discriminates the dynamics of the system from the behaviour of a classical spin-glass

1H\text{}^1H NMR on (NixMn1−x)3[Cr(CN)6]2⋅nH2O(Ni_xMn_{1-x})_3[Cr(CN)_6]_2 \cdot nH_2O

We report on $\text{}^1H$ NMR of $(Ni_xMn_{1-x})3[Cr(CN)_6]_2 \cdot 15H_2O$ hexacyanochromates, where x changes from 0 to 1. The decay time constants of the free induction decay signals described by an effective spin-spin relaxation time $T_{2eff}$ obtained from M(t) = $M_0 \text{exp}(t//T_{2eff})$ decrease as the local magnetic moments increase produced by the magnetic transition metal ions at the sites of the resonant $\text{}^1H$ nuclei. The recovery of the magnetization in the spin-lattice relaxation time $(T_1)$ experiments was single-exponential