Large magnetoresistance anomalies in Dy7Rh3

The compound Dy7Rh3 ordering antiferromagnetically below (TN=) 59 K has been known to exhibit a temperature (T) dependent electrical resistivity (rho) behavior in the paramagnetic state unusual for intermetallic compounds in the sense that there is a broad peak in rho(T) in the paramagnetic state (around 130 K) as though there is a semi-conductor to metal transition. In addition, there is an upturn below T_N due to magnetic super-zone gap effects. Here we report the influence of external magnetic field (H) on the rho(T) behavior of this compound below 300 K. The rise of rho(T) found below TN could be suppressed at very high fields (>> 60 kOe), thus resulting in a very large magnetoresistance (MR) in the magnetically ordered state. The most notable finding is that the magnitude of MR is large for moderate applications of H (say 80 kOe) in a temperature range far above T_N as well, which is untypical of intermetallic compounds. Thus, this compound is characterized by large MR anomalies in the entire T range of investigation.Comment: IOP Selec

Multiphase magnetic deflagrations in a Nd5Ge3 single crystal

We report magnetic deflagration phenomena ocurring in both antiferromagnetic and ferromagnetic phases in a single crystal of the intermetallic compound Nd5Ge3. We have investigated, using a trigger heat pulse, the spatial and time-resolved evolution of induced magnetic avalanches as a function of the applied magnetic field. The experimental data fit well with the theory of magnetic deflagration

Comparative Toxicity of Tapentadol and Tramadol Utilizing Data Reported to the National Poison Data System

BackgroundTapentadol (TAP) and tramadol (TRA) provide pain relief through similar monoaminergic and opioid agonist properties.ObjectiveTo compare clinical effects and medical outcomes between TAP and TRA exposures reported to the National Poison Data System of the American Association of Poison Control Centers.MethodsA retrospective cohort study was conducted analyzing national data for single medication TAP or TRA cases reported from June 2009 through December 2011. Case outcomes, dichotomized as severe versus mild; clinical effects; and use of naloxone were compared.ResultsThere were 217 TAP and 8566 TRA cases. Significantly more severe outcomes were associated with TAP exposures for an all-age comparison (relative risk [RR] = 1.24; 95% CI = 1.04-1.48), and for the <6-year-old age group (RR = 5.76; 95% CI = 2.20-15.11). Patients with TAP exposures had significantly greater risk of respiratory depression (RR = 5.56; 95% CI = 3.50-8.81), coma (RR = 4.16; 95% CI = 2.33-7.42), drowsiness/lethargy (RR = 1.38; 95% CI = 1.15-1.66), slurred speech (RR = 3.51; 95% CI = 1.98-6.23), hallucination/delusion (RR = 7.25; 95% CI = 3.61-14.57), confusion (RR = 2.54; 95% CI = 1.56-4.13) and use of naloxone (RR = 3.80; 95% CI = 2.96-4.88). TRA exposures had significantly greater risk of seizures (RR = 7.94; 95% CI = 2.99-20.91) and vomiting (RR = 1.96; 95% CI = 1.07-3.60).ConclusionTAP was associated with significantly more toxic clinical effects and severe outcomes consistent with an opioid agonist. TRA was associated with significantly higher rates of seizures and vomiting

High Frequency Permeability of Mn-Zn Ferrite and its Composite Materials

Complex permeability spectra (μ*=μ'-iμ") in Mn-Zn ferrite and its composite materials have been studied. In sintered ferrite, resonance-type frequency dispersion was observed at room temperature but decrement of μ' is steeper than that of ordinary resonance. As the temperature is decreased, onset frequency of dispersion shifts higher and dispersion character changes to relaxation-type. In ferrite composite materials, relaxation characters were also observed at low volume loading samples. Since Mn-Zn ferrite has relatively high electrical conductivity at room temperature, high frequency permeability is suppressed by eddy current. However, lowering of temperature and reduction of ferrite content result in the decrease of eddy current; magnetic resonance such as relaxation-type spin rotational one appears in high frequency region

Competition of two-ion and single-ion anisotropy in rare-earth systems: Large anisotropy example of Tb₅ Ge₃

Contains fulltext : 83572.pdf (publisher's version ) (Open Access)7 p