Origin of cluster spin glass and nuclear Schottky anomaly in Mn

The magnetic ground state of the Mn50Ni38.5Sn11.5 alloy is investigated through dc/ac magnetization and low-temperature $(\geq0.15\ \text{K})$ specific-heat $(C_{p}(T))$ measurements. The dc and ac magnetization measurements indicate that the system can be identified as a cluster spin glass (CSG) phase in a ferromagnetic (FM) background, and as a conjunction of these two phases an exchange bias effect (EBE) is observed in this system. The presence of coexisting phases is further supported by our $C_{p}(T)$ measurement. We attribute the existence of the CSG phase to the antiferromagnetic (AFM) interaction arising from the Mn-Mn antisite disorder which further enhances through martensite transformation. The anomalous increase of Cp below 0.7 K is due to the nuclear Schottky anomaly arising from the hyperfine splitting of the nuclear levels of Mn atoms. Detailed reasons for the observed behaviours are discussed in the paper

Anomalous magnetoresistive behavior in Ni44Co2Mn43In11 alloy

We conducted the temperature (T) and magnetic field (H) dependence of resistivity (ρ) on Ni44Co2Mn43In11 compound under the magnetic field (H=) 0-70 kOe in the temperature range T=150-380 K. Several novel anomalies are observed in the ρ(T,H) behaviour of this compound which upto our knowledge were not reported earlier in these systems. An unusual change in ρ(T) associated with a positive manetoresistance (MR) is also observed just above the martensite transformation (MT) in the temperature range of T=308-320 K. In addition, an anomalous field dependence of the MR is observed in temperature region T=305-310 K, where ρ increases with H after reaching minimum. Furthermore, a large MR up to -65 % is observed across its room temperature MT which can be beneficial for practical applications. The possible origin of the observed MR behaviour is discussed in terms enhanced magnetic scattering

Comparison of health effects between individuals with and without skin lesions in the population exposed to arsenic through drinking water in West Bengal, India

A study was conducted to explore the effect of arsenic causing conjunctivitis, neuropathy and respiratory illness in individuals, with or without skin lesions, as a result of exposure through drinking water, contaminated with arsenic to similar extent. Exposed study population belongs to the districts of North 24 Parganas and Nadia, West Bengal, India. A total of 725 exposed (373 with skin lesions and 352 without skin lesions) and 389 unexposed individuals were recruited as study participants. Participants were clinically examined and interviewed. Arsenic content in drinking water, urine, nail and hair was estimated. Individuals with skin lesion showed significant retention of arsenic in nail and hair and lower amount of urinary arsenic compared to the group without any skin lesion. Individuals with skin lesion also showed higher risk for conjunctivitis ((odd’s ratio) OR: 7.33, 95% CI: 5.05–10.59), peripheral neuropathy (OR: 3.95, 95% CI: 2.61–5.93) and respiratory illness (OR: 4.86, 95% CI: 3.16–7.48) compared to the group without any skin lesion. The trend test for OR of the three diseases in three groups was found to be statistically significant. Again, individuals without skin lesion in the exposed group showed higher risk for conjunctivitis (OR: 4.66, 95% CI: 2.45–8.85), neuropathy (OR: 3.99, 95% CI: 1.95–8.09), and respiratory illness (OR: 3.21, 95% CI: 1.65–6.26) when compared to arsenic unexposed individuals. Although individuals with skin lesions were more susceptible to arsenicinduced toxicity, individuals without skin lesions were also subclinically affected and are also susceptible to arsenic-induced toxicity and carcinogenicity when compared to individuals not exposed to arsenic