Varying magnetic fields and temperature conditions help to elucidate smart materials' transitory magnetic disorder

January 28, 2013

Novel, smart materials like shape memory alloys very often display so-called glass-like magnetism. Other smart materials with similar properties include those which, when exposed to a magnetic field, change their electrical resistance, known as manganites, or change their temperature, known as magnetocaloric materials.  Kaustav Mukherjee and his colleagues from the Consortium for Scientific Research Indore in India studied a key stage in the formation of such a magnetic glass material, called Pr0.5 Ca0.5 Mn0.975 Al0.025 O3, in a paper about to be published in European Physical Journal B.

They focused on the stage where 'water to ice' style transformation—referred to as first-order magnetic transformation— is arrested upon cooling. This is a phenomenon dubbed kinetic arrest, corresponding to a temperature where the material undergoes a transition from a magnetic to a non-magnetic state, with the two phases competing with each other.

Glass-like display fragile magnetic properties. They draw their name from the similarity to the fragility observed in conventional, chemical glass. If a magnetic field is applied while the sample is cooled to what is referred to as its , magnetisation of the sample increases and the material becomes magnetic. However, the magnetisation continues to increase further with time, even if the magnetic field and temperature remain constant.

The authors performed bulk measurements of magnetisation on powder samples of Pr0.5 Ca0.5 Mn0.975 Al0.025 O3, at the between magnetic and non-. To do so, they simultaneously varied both the magnetic field and the temperature of the sample. They observed the formation of the kinetic arrest band and showed that it is inversely correlated with states reached at extremes of temperature described at supercooling and superheating bands. They then established that the kinetic arrested state is different from the supercooled state.

Explore further: X-ray resonance scattering can reveal the magnetic properties of transition metal oxides made out of heavy elements

More information: K. Mukherjee, Kranti Kumar, A. Banerjee and P. Chaddah (2013), On the correlation between supercooling, superheating and kinetic arrest in a magnetic glass Pr0.5Ca0.5Mn0.975Al0.025O3, European Physical Journal B, DOI 10.1140/epjb/e2012-30748-y

Related Stories

Combining opposing properties for synergistic function

June 27, 2012

The properties of nanomaterials often differ in novel ways from those of the bulk material of the same substances. European researchers investigated a completely new class of such materials that could be important for magnetic ...

Magnetic spin on non-magnetic materials

February 14, 2012

(PhysOrg.com) -- Nanotechnologists from the University of Twente's MESA+ and MIRA research institutes have developed a method for incorporating magnetic elements into non-magnetic materials in a highly controlled way. Using ...

Recommended for you

Probe for nanofibers has atom-scale sensitivity

January 20, 2017

Optical fibers are the backbone of modern communications, shuttling information from A to B through thin glass filaments as pulses of light. They are used extensively in telecommunications, allowing information to travel ...

Magnetic recording with light and no heat on garnet

January 19, 2017

A strong, short light pulse can record data on a magnetic layer of yttrium iron garnet doped with Co-ions. This was discovered by researchers from Radboud University in the Netherlands and Bialystok University in Poland. ...

Studying the quantum vacuum: Traffic jam in empty space

January 18, 2017

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by Professor Alfred Leitenstorfer has now shown how to manipulate the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.