Magnetic systems at criticality: different signatures of scaling

Different aspects of critical behaviour of magnetic materials are presented and discussed. The scaling ideas are shown to arise in the context of purely magnetic properties as well as in that of thermal properties as demonstrated by magnetocaloric effect or combined scaling of excess entropy and order parameter. Two non-standard approaches to scaling phenomena are described. The presented concepts are exemplified by experimental data gathered on four representatives of molecular magnets.Comment: 33 pages, 16 figure

Magnetic Properties of NdFe0.9Mn0.1O3

In our paper we study effect of Mn for Fe substitution on magnetic properties of NdFex-1MnxO3 compounds for x = 0 and 0.1, which have been grown by the OFZ technique. The Neel temperature decreases from T-N1 = 691 K to T-N1 = 621 K, and the anomaly in AC susceptibility, related to spin reorientation, vanishes with Mn substitution. Low temperature heat capacity measurement for sample with x = 0.1 revealed that substitution of Mn for Fe shifts a Schottky-type anomaly at T-sh to higher temperatures. Another anomaly is generated by doping at T-max = 11 K. The anomaly is smeared out by magnetic field, confirming its magnetic origin.15th Czech and Slovak Conference on Magnetism (CSMAG), Jun 17-21, 2013, Kosice, Slovaki

SOSIALISASI EFEKTIVITAS PEMILU DALAM MEMBERIKAN PEMAHAMAN POLITIK GUNA MENINGKATKAN KESADARAN BERPOLITIK MASYARAKAT

The purpose of this journal is to provide broader knowledge related to the effectiveness of elections in providing political understanding in order to increase political awareness of the Kukerta student community at the University of Riau consistently trying to increasing community participation, especially Kuala Lemang Village, Keritang Subdistrict, Indragiri Regency downstream for the prevention of abstentions. the activities carried out by Kukerta students at the University of Riau and the village head of Kuala Lemang were to socialize the election to the people who were present, explain in detail the importance of elections in social life after which students also made videos which were uploaded to YouTube related to election socialization

Magnetic properties of NdMn

Magnetization, AC susceptibility and specific heat measurements were performed on polycrystalline NdMn1-xFexO3+δ compounds (x = 0.0, 0.1 and 0.2). Substitution of Fe for Mn reduces the Néel temperature TN, which is associated with magnetic ordering of Mn sublattice, from 85.5 K to 57.0 K. The temperature dependence of magnetization for x = 0.2 exhibits the compensation temperature and the pole inversion below Tcomp = 26.7(5) K. Initial magnetization curves present a remnant magnetization in the ordered region with the sign of remnant magnetization depending on temperature. The substitution of Fe for Mn changes hysteresis loop of NdMnO3+δ from the ferromagnetic-like one (μ0Hc = 0.09 T) by expanding the width of the loop (μ0Hc = 0.55 T) for x = 0.1 and then shrinking the central part of the loop to “butterfly” type (μ0Hc = 0.35 T) for x = 0.2

Magnetic properties of NdMn1-xFexO3+δ system

Magnetization, AC susceptibility and specific heat measurements were performed on polycrystalline NdMn1-xFexO3+δ compounds (x = 0.0, 0.1 and 0.2). Substitution of Fe for Mn reduces the Néel temperature TN, which is associated with magnetic ordering of Mn sublattice, from 85.5 K to 57.0 K. The temperature dependence of magnetization for x = 0.2 exhibits the compensation temperature and the pole inversion below Tcomp = 26.7(5) K. Initial magnetization curves present a remnant magnetization in the ordered region with the sign of remnant magnetization depending on temperature. The substitution of Fe for Mn changes hysteresis loop of NdMnO3+δ from the ferromagnetic-like one (μ0Hc = 0.09 T) by expanding the width of the loop (μ0Hc = 0.55 T) for x = 0.1 and then shrinking the central part of the loop to “butterfly” type (μ0Hc = 0.35 T) for x = 0.2

Butterfly-like Heteronuclear 3d–4f Metal Clusters: Synthesis, Structures, Magnetic Properties, and Magnetocaloric Effect

This study describes the self-assembled synthesis, characterization, and structural features of two new heterometallic Fe6Ln clusters, [Fe6Ln(μ3-OH)2(mdea)6(N3)6(NO3)] (Ln = Y (1), Gd (2); mdeaH2 = N-methyldiethanolamine). The obtained compounds possess a unique crystalline structure with a vertex-sharing butterfly-like Fe3LnFe3 motif and a rare type of 2,3,4M7-1 topology. The compounds show a new prototype structure with a distinctive arrangement of a lanthanide center between the Fe3 triangles. Magnetic properties of the obtained clusters were investigated in detail. In 1, the best fit through a spin Hamiltonian to the experimental data of both magnetic susceptibility and magnetization curves gave J values ranging from −5.5 to −11.1 cm–1. In 2, these values vary from −18.0 to −31.5 cm–1. The cluster 2 also showed a magnetocaloric effect (MCE) with a −ΔSm value of 10.6 J kg–1 K–1 (16.3 J mol–1 K–1) at 2.0 K. This effect is superior to that of other metallacrown compounds (with one Gd inside of an antiferromagnetic matrix of iron centers). The obtained compounds bring a new example of heptametallic clusters into a family of heteronuclear iron(III)-lanthanide derivatives with notable structural characteristics and magnetic behavior. © 2021 American Chemical Societ

Magnetic Properties of La

Magnetic properties of La0.8K0.2MnO3have been studied on nanoparticles prepared by glycine – nitrate method. As prepared nanoparticles and samples annealed at 300°C/2 hours adopt orthorhombic crystal structure (space group Pbnm). Crystal structure and particles size were modified by heat treatment. The exchange bias effect was observed on samples with particles size smaller than 50 nm.Cooling in magnetic field Hcf≠ 0 through the Curie temperature TCshifts hysteresis loop in horizontal and vertical direction. The values of exchange bias field HE, coercive field Hc, remnant asymmetry μE and coercive magnetization μc increase with increasing value of cooling field Hcf. In addition the training effect was studied. Basic magnetic properties like the Curie temperature TC and the saturated magnetization μsincrease and HE or μE decrease with heat treatment. Heat treatment at 600 °C/2 hours increases the average size of nanoparticles to about 60 nm, crystal structure changes to rhombohedral structure (space group R$\bar 3$c) and EB effect vanishes