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Journal : Jurnal Sains Materi Indonesia

PENENTUAN STRUKTUR MAGNETIK CaMnO3 DENGAN DIFRAKSI NEUTRON Suharno, Suharno; Purwanto, Agus; Fajar, Andika; Kurniawan, Budhy; Mugihardjo, Herry; Adi, Wisnu Ari
Jurnal Sains Materi Indonesia Edisi Khusus, Oktober 2006
Publisher : Center for Science & Technology of Advanced Material - National Nuclear Energy Agency of

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Abstract

PENENTUAN STRUKTUR MAGNETIK CaMnO3 DENGAN DIFRAKSI NEUTRON. Informasi mengenai struktur magnetik tidak dapat diperoleh melalui difraksi sinar-X (XRD). Oleh karena itu dibutuhkan data yang berasal dari difraksi neutron. Struktur magnetik CaMnO3 dalam penelitian ini dijelaskan melalui difraksi neutron metode serbuk. Preparasi sampel CaMnO3 mula-mula mencampur bahan dasar melalui perhitungan kimia, setelah itu dilanjutkan melalui proses milling dengan variasi waktu dan variasi pemanasan. Dari hasil karakterisasi melalui difraksi sinar-X diperoleh bahwa, fasa baru CaMnO3 terbentuk pada milling selama 12 jam dan pemanasan 1000 ºC selama 9 jam. Sistem kristal berada pada sistem simetri orthorhombik dengan group ruang (Pnma -D162h) dan parameter kisi (di suhu 12 K), a = 5,2801 Å, b = 7,4432 Å, c = 5,2588 Å. CaMnO3 memiliki suhu Neel di 131 K[3], artinya bahan ini berubah sifat menjadi antiferomagnetik jika berada di bawah suhu Neel. Hasil difraksi neutron CaMnO3, sifat magnetik muncul pada atom Mn di suhu 12 K sudut 2θ=24,486 bidang pantulan hkl (011) dengan struktur magnetik pada atom Mn di posisi simetri 4b(0,0,½) adalah nonkolinear antiferromagnetik dan momen magnetiknya m(Mn) = 1,73 μB.
PENURUNAN KONFIGURASI MOMEN MAGNETIK INCOMMENSURATE CeCu5,5Au0,5 DENGAN VEKTOR PROPAGASI Q = (QX, 0, 0) Purwanto, Agus
Jurnal Sains Materi Indonesia Vol 3, No 3: JUNI 2002
Publisher : BATAN

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Abstract

PENURUNAN KONFIGURASI MOMEN MAGNETIK INCOMMENSURATE CeCu5,5Au0,5 DENGAN VEKTOR PROPAGASI Q = (QX, 0, 0). Telah dilakukan penurunan konfigurasi momen magnetik yang mungkin muncul dari paduan CeCu5,5Au0,5 pada fasa antiferomagnetik incommensurate temperatur rendah dengan vector gelombang magnetik (qx, 0, 0). Paduan tersebut membentuk kristal ortorombik bertipe struktur CeCu6 dengan grup ruang Pnma dan mengalami transisi magnetik pada suhu 1,07 K. Analisis, yang dilakukan dengan teori representasi, terutama dilakukan untukmembahas konfigurasi denganmodulasi sinusoidal. Hasilnya adalah empat konfigurasi dengan vektor propagasi gelombang magnetik searah dengan sumbu-a, yaitu: dua konfigurasi dengan arah momen sejajar sumbu-b dan 2 konfigurasi lain dengan arahmomen pada bidang ab.
CONSTANT-Q CONFIGURATION OF 3-AXIS SPECTROMETER Purwanto, Agus
Jurnal Sains Materi Indonesia Vol 7, No 3: JUNI 2006
Publisher : BATAN

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Abstract

CONSTANT-Q CONFIGURATION OF 3-AXIS SPECTROMETER. The constant-q method has been widely used in the 3-axis spectrometer, which requires more angles to be setup as compared to those of the diffractometer. Those angles are not natural variables in the physical quantities of interest for the dynamic properties of materials. As the physical quantities of interests are the energy and momentum transfer, those angles must be converted into the energy and momentum transfer. To the author’s knowledge, although this method has been known since around 1960’s, no literature sufficiently describes the details to provide the necessary equations. This paper elaborates the conversion by using the energy and momentum conservation with the vector and trigonometric consideration of the scattering processes in the reciprocal space. The angle values resulted from this conversion might be used to obtained the dispersion relation measurement by utilizing the 3-axis spectromenter.
DOUBLE AXIS MODE OF BATAN’S TRIPLE AXIS SPECTROMETER Purwanto, Agus; Santoso, Eddy; Hafid, Irfan; Muslih, M. Refai
Jurnal Sains Materi Indonesia Vol 7, No 2: FEBRUARI 2006
Publisher : BATAN

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Abstract

DOUBLE AXIS MODE OF BATAN’S TRIPLE AXIS SPECTROMETER. Triple Axis Spectrometer (TAS), which is an indispensible tool to microscopically probe inelastic scattering processes in condensed matter, has been installed at the Neutron scattering Laboratory of the R & D Center for Materials Science & Technology, BATAN, since 1992. However, the control and data acquisition system have been nonfunctional since 1996. Following an in-house development of the alternative control and data acquisition hardware last year, TAS started to show the capability and reliability of handling the measurement in the double axis mode. This paper reports a double axis mode control and data acquisition software development which benefits from the hardware development.
POSSIBLE NONCOLLINEAR MAGNETIC STRUCTURES ON CAMNO3 AND LaMNO3 Purwanto, Agus
Jurnal Sains Materi Indonesia Edisi Khusus, Oktober 2006
Publisher : Center for Science & Technology of Advanced Material - National Nuclear Energy Agency of

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Abstract

POSSIBLE NONCOLLINEAR MAGNETIC STRUCTURES ON CAMNO3 AND LaMNO3. CAMNO3 and LaMNO3 ceramics crystallize in the orthorhombic Pnma and monoclinic P1121/a space group, respectively. It has been reported that the ceramics order collinear antiferromagnetically below T=140K and 130K, respectively. The manganese magnetic atoms in CAMNO3 are located in the 4(b) site, while those in LaMnO3 are in 2(c) and 2(d). As the manganese atoms are neither located in the rotation axis or the mirror plane of the crystallographic symmetry, the noncollinear arrangements should not be excluded. This paper reports the derivation of the possible magnetic structures of CAMNO3 and LaMnO3. The derivation is based on the magnetic(Shubnikov) space group and the group theory. The result is that all of the possible models allow for three moment components in the noncollinear arrangements. The possible magnetic structures for CAMNO3 are noncollinear antiferromagnetic, noncollinear ferromagnetic in the a-direction, noncollinear ferromagnetic in the b-direction, noncollinear ferromagnetic in the c-direction. The possible magnetic structures for LaMnO3 are noncollinear ferromagnetic in the c-direction and in the ab-plane.
Co-Authors - Isdiyarto . HERNAYANTI . HERY WINARSI Abdurohman Muslim Abdurrahman, Naufal Adhy Karyo Nugroho Adi Putra Setianto Adila Ashari Partono, Adila Ashari Adimas Wahyu Saputro Agung Budiarto, Agung Agustikasa, Dyah Kurniawati Akhmad Aminuddin Bama, Akhmad Aminuddin Alice Yuniati Alqodri, Achmad Fatih Andika Fajar Andreani Hanjani Anggun Nugroho, Anggun Anif Jamaluddin Anindita Putri Nurmalita Sari Anisa Agni Putri Aris Mukimin Arkhan Subari Artawan, I Nengah Arum Purwandari Bagus, Asep Bhagas Adhitya Ardia Pratama Bintoro Anang Subagyo, Bintoro Anang Budhy Kurniawan Budiwati Budiwati Budiyono Budiyono Chintya Fadila Laksmitaningrum Dadan Rosana Darmadi, Eko Agus Decy Lukitasari DEDDY MUCHTADI Dewitasari, Dinny Islamiah Dhanindra Prabowo, Dhanindra Dina Dina, Dina Dwi Harjanto, Ganang Dwi Ratmono Eddy Santoso Endang Kwartiningsih Endang Mastuti Eny Sri Widyastuti Erika Rani Eva Oktavia Ningrum, Eva Oktavia Febryanita, Renna Firdaus, Muhammad Sai FRANSISKA RUNGKAT ZAKARIA Gde Sastrawangsa, Gde Hanny Vistanty, Hanny Hatmoko, Bayu Dwi Hendri Widiyandari Heny Kusumayanti HERNAYANTI HERNAYANTI Heru Sukamto, Heru HERY WINARSI I Kadek Ariana, I Kadek Ida Hayu Dwimawanti Ihyaul Ulum Imam Ghozali Indah Nuraeni Intan Fatimah Hizbullah, Intan Fatimah Irfan Hafid Irnaning Handayani, Novarina Ischiadica Elharomy Isni Nurruhwati Jidanah Darmiyati Jumari, Arif Kuncoro Diharjo Kusumadewi, RR Karlina Aprilia Lila Yuwana Lilik Eka Radiati M. Refai Muslih Mety Nuraini Miratul Atiqah Mugihardjo, Herry Muhammad Baru Herman, Muhammad Baru Muhammad Setio Priambodo, Muhammad Mulyadi, Eka Octaviyatna Mulyoto ,, Mulyoto Nilawati Nilawati Nugraheni, Anggiyani Ratnaningtyas Eka Nur Cahyonowati Nur Kadarisman Nur Zen, Nur Nurkholis Nurkholis Nurtjahjo Dwi Sasongko Nur’aini, Anafi Oktita Earning Hanifah Paryanto Prasetiyo, Agus Eko Purwaningrum, Fajar Adhi Rafika Rahmawati Rahma Ayu Maharani Rame Rame, Rame Rame, Rame Ratnawati Ratnawati Reny Yesiana, Reny Richardus Eko Indrajit Risha Aristiani N, Risha Rosita, Galuh Chynintya Rosita Ruliaty, Lisa Sari, Septi Shofwan Hanief, Shofwan Silvy Djayanti, Silvy Siwi P. M. Wijayanti Siwi P.M. Wijayanti SIWI PRAMATAMA MARS WIJAYANTI Stephani Novitasari Christianingsih Kaluti Suharno Suharno Suharto, Toni Suharto, Toni Sumarna Sumarna Sumarna, . Sumarno Sumarno Suratsih Suratsih Taufiq Bagus Prasojo Wicaksono, Kukuh Aryo Wisnu Ari Adi Yohanes Dwi Saputra, Yohanes Dwi Yuniar Mulyani Yuvita Avrie Diany