Observation of low temperature metastable states in complex CaMnO.

J Phys Condens Matter

Magnetics and Advanced Ceramics Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.

Published: February 2018

The low temperature magnetic behaviour of the multiferroic quadruple perovskite CaMnO is investigated. The magneto-caloric effect in this material is presented for the first time. Along with the established magnetic transitions, T ~ 90 K and T ~ 45 K, an anomaly at 20 K is observed in our dc magnetization, ac susceptibility and dielectric measurements; below which, an inverse magnetocaloric effect is also observed in our  -ΔS (T) plots. The neutron scattering measurements show minimal change between 10 K and 30 K in static correlations, but a clear change in energy and linewidth of the magnetic excitations is evident. The results suggest that only dynamic correlations change across T ~ 20 K. The existence of multiple magnetic interactions below 45 K, with significant coupling between them, is demonstrated using an Arrott plot analysis of our magnetic data. Compatible conclusions are drawn from magnetocaloric plots. The peak change in isothermal magnetic entropy (-ΔS ) is 1.3 JK kg and the value of refrigeration capacity in CaMnO is 34.5 J · kg at 7 T.

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-648X/aaa525DOI Listing

Publication Analysis

Top Keywords

low temperature
8
magnetic
6
observation low
4
temperature metastable
4
metastable states
4
states complex
4
complex camno
4
camno low
4
temperature magnetic
4
magnetic behaviour
4

Similar Publications

Micelles, liposomes, and solid lipid nanoparticles (SLNs) are promising drug delivery vehicles; however, poor aqueous stability requires post-processing drying methods for maintaining long-term stability. The objective of this study was to compare the potential of lipid-based micelles, liposomes, and SLNs for producing stable re-dispersible spray-dried powders with trehalose or a combination of trehalose and L-leucine. This study provides novel insights into the implementation of spray drying as a technique to enhance long-term stability for these lipid-based nanocarriers.

View Article and Find Full Text PDF

Life History Strategies of the Winter Annual Plant (Asteraceae) in a Cold Desert Population.

Plants (Basel)

January 2025

Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou 730000, China.

Turcz. is a winter annual species of the Asteraceae family, distributed in sandy areas of northern China, and is crucial for wind avoidance and sand fixation. To understand the inter- and intra-annual population dynamics of in its cold desert habitats, we conducted long- and short-term demographic studies to investigate the timing of germination, seedling survival, soil seed bank and seed longevity of natural populations on the fringe of the Tengger Desert.

View Article and Find Full Text PDF

Climate Change-Induced Decline in Succulent in Namibia's Arid Regions.

Plants (Basel)

January 2025

Department of Plant and Soil Sciences, University of Pretoria, Hatfield, Pretoria P.O. Box X20, South Africa.

The global rise in temperatures due to climate change has made it difficult even for specialised desert-adapted plant species to survive on sandy desert soils. Two of Namibia's iconic desert-adapted plant species, and the quiver tree , have recently been shown to be under threat because of climate change. In the current study, three ecologically important Namibian milk bushes were evaluated for their climate change response.

View Article and Find Full Text PDF

The Gene Enhances the Cold Resistance of .

Plants (Basel)

January 2025

College of Life Sciences, Shihezi University, Shihezi 832000, China.

Plants have large amounts of the late embryogenesis abundant protein (LEA) family of proteins, which is involved in osmotic regulation. The Korla Pear () is an uncommon pear species that thrives in Xinjiang and can survive below-freezing conditions. We found that the gene was more expressed after cold treatment by looking at the transcriptome data of the Korla Pear.

View Article and Find Full Text PDF

Numerical Simulation of Airflow Organization in Vulcanization Tanks for Waste Tires.

Polymers (Basel)

January 2025

College of Mechanical and Electrical Engineering, Qingdao University, Qingdao 266071, China.

Currently, in the domestic practice of retreading tires using vulcanization tanks, some tanks exhibit uneven temperature distributions leading to low retreading success rates. To address that, this paper simulated the temperature and velocity fields during the heating process of vulcanization tanks for waste tire retreading. The results indicated that a higher heating power reduces the time required for the vulcanizing agent to reach the vulcanization condition, but it also increases the difference in tire temperature in the tank, with a severely uneven distribution of the temperature field.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!