Ni1-xCrx alloy for self controlled magnetic hyperthermia

It is known now that an increase in tumor temperature decreases the tumor resistance to chemo- and radiation therapies. Hyperthermia treatment of the tumor cells where damage to the healthy cells can be avoided is viable by using magnetic nanoparticles with controlled Curie temperatures. Nickel-Chromium (Ni1-xCrx) particles with varying compositions have been investigated as thermoseeds for use in localized self controlled hyperthermia treatment of cancer. A series of Ni1-xCrx alloys, have been prepared to find the specific composition which has Curie temperature around 316-317 K. The samples were cast by arc melting technique, and were annealed at 850 degrees C for 5 hours in sealed quartz tubes. Magnetic properties of the samples were investigated, including Curie temperature, saturation magnetization and hysterisis using Superconducting Quantum Interference Device (SQUID) and Vibrating Sample Magnetometer (VSM). The Curie temperatures of the alloys were found to decrease almost linearly from 401 K to 289 K as the Cr concentration was increased from x = 4.54 wt % to x = 5.90 wt %. The results showed that Ni1-xCrx alloys might be good candidates for self regulating magnetic hyperthermia applications. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim