ﻻ يوجد ملخص باللغة العربية
The ferromagnetic (FM) nature of the metallic LaCo$_2$P$_2$ was investigated with the positive muon spin rotation, relaxation and resonance ($mu^+$SR) technique. Transverse and zero field $mu^+$SR measurements revealed that the compound enters a long range FM ground state at $T_{rm C}=130.91(65)$~K, consistent with previous studies. Based on the reported FM structure, the internal magnetic field was computed at the muon sites, which were predicted with first principles calculations. The computed result agree well with the experimental data. Moreover, although LaCo$_2$P$_2$ is a paramagnet at higher temperatures $T>160$~K, it enters a short range ordered (SRO) magnetic phase for $T_{rm C}<Tleq160$~K. Measurements below the vicinity of $T_{rm C}$ revealed that the SRO phase co-exists with the long range FM order at temperatures $124leq Tleq T_{rm C}$. Such co-existence is an intrinsic property and stems from competition between the 2D and 3D interactions/fluctuations.
The magnetic properties of the layered oxypnictide LaMnAsO have been revisited using neutron scattering and magnetization measurements. The present measurements identify the N{e}el temperature $T_N$ = 360(1) K. Below $T_N$ the critical exponent descr
In this study, we performed powder neutron diffraction and inelastic scattering measurements of frustrated pyrochlore Nd$_2$Ir$_2$O$_7$, which exhibits a metal-insulator transition at a temperature $T_{rm MI}$ of 33 K. The diffraction measurements re
Er$_2$Sn$_2$O$_7$ remains a puzzling case among the extensively studied frustrated compounds of the rare-earth pyrochlore family. Indeed, while a first order transition towards a long-range antiferromagnetic state with the so-called Palmer-Chalker st
We present observations of highly frustrated quasi two-dimensional (2D) magnetic correlations in the honeycomb lattice layers of the S$_{eff}$ = 1/2 compound $gamma$-BaCo$_2$(PO$_4$)$_2$ ($gamma$-BCPO). Specific heat shows a broad peak comprised of t
In order to study the phase diagram from a microscopic viewpoint, we have measured wTF- and ZF-$mu^+$SR spectra for the Sr$_{1-x}$Ca$_x$Co$_2$P$_2$ powder samples with $x=0$, 0.2, 0.4, 0.5, 0.6, 0.8, and 1. Due to a characteristic time window and spa