Related Experiment Video
Updated: Jun 3, 2026
11:07
Synthesis of Non-uniformly Pr-doped SrTiO3 Ceramics and Their Thermoelectric Properties
Published on: August 15, 2015
High temperature magnetic ordering in the 4d perovskite SrTcO3
Efrain E Rodriguez1, Frédéric Poineau, Anna Llobet
1NIST Center for Neutron Research, National Institute of Science and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20889, USA.
Physical Review Letters
|March 17, 2011
Summary
Strontium technetate (SrTcO3) exhibits an exceptionally high magnetic ordering temperature, nearing 750 °C, without using 3d transition elements. This discovery highlights a strong link between electronic structure and magnetic properties in novel materials.
Area of Science:
- Materials Science
- Solid State Physics
- Magnetism
Background:
- Investigating magnetic materials without 3d transition elements is crucial for developing new technologies.
- High magnetic ordering temperatures are desirable for many applications.
Purpose of the Study:
- To present evidence for a high magnetic ordering temperature in a compound lacking 3d transition elements.
- To characterize the magnetic and structural properties of Strontium Technetate (SrTcO3).
Main Methods:
- Neutron powder diffraction was employed on SrTcO3 samples.
- Electronic structure calculations were performed to understand electronic interactions.
Main Results:
- SrTcO3 was found to possess a distorted perovskite structure with G-type antiferromagnetic ordering.
- An exceptionally high Néel temperature close to 750 °C was observed.
- A magnetic moment of 1.87(4)μB per Tc cation was measured at room temperature.
Conclusions:
- SrTcO3 demonstrates one of the highest magnetic ordering temperatures reported for compounds without 3d transition elements.
- Extensive hybridization between technetium 4d and oxygen states influences magnetic properties.
- A strong correlation exists between magnetic ordering temperature and moment formation in SrTcO3.
Related Concept Videos
01:31Ferromagnetism
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
01:30Paramagnetism
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
01:16Thermal Sigmatropic Reactions: Overview
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred to as...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred to as...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.